Category Archives: 2019 General Election

What impact did the Brexit Party have in the 2019 general election?

by John Curtice, Stephen Fisher and Patrick English

One of the most dramatic developments during the campaign for the December 2019 general election, whose second anniversary is this weekend, was the decision announced by Nigel Farage on 11 November that the Brexit Party would not contest those seats being defended by the Conservatives. Instead it would concentrate its firepower on those seats currently in the hands of one of the opposition parties. This represented a substantial retreat for a party that just the previous May had topped the poll in the European elections.

But was the decision as important as it was dramatic? Part of the answer to that question depends, of course, on the impact the decision had on the overall popularity of the party where it was continuing to fight. It almost certainly helped to reduce it. In the week leading up to Mr Farage’s announcement, the Brexit Party stood on average in the polls at 16% among those who had voted Leave in the 2016 EU referendum. (It had no measurable support at all among Remain supporters.) A week later, its support among Leave voters had fallen by five points to 11% (while support for the Conservatives was up by five points). By polling day, the party was down to just 4%.

Of course, much of this drop would have been occasioned by the gradual realisation among voters in the relevant seats that the Brexit Party was not standing locally, though the scale of the drop by polling day is too big to be explained by that alone. Equally, some voters will have switched away from the party for reasons that had nothing to do with Mr Farage’s decision. But it certainly looks highly likely that the Brexit Party’s partial withdrawal helped to undermine its level of support where it continued to stand.

Even so, the party still managed to win an average of 5.7% of the vote in those seats in England & Wales that it did fight – potentially enough to have some impact on the relative fortunes of the other parties. But what impact did it have? Mr Farage’s decision appeared to reflect his oft made claim that his party was able to gain the support of voters in Labour-inclined, more working class constituencies that the Conservatives could never reach. Thus, while standing down in Conservative-held seats might help avoid a split in the Leave vote that could help the opposition parties to gain Conservative-held seats, continuing to contest opposition-held seats might help the pro-Brexit Conservatives to gain Labour-held seats and thus the overall majority that Boris Johnson was seeking.

The success or otherwise of this strategy is addressed in our analysis of the constituency election results in the recently published ‘Nuffield’ study of the last election, The British General Election of 2019. It proved far from an easy question to answer.

We could, of course, look at the choices that those who voted for the Brexit Party in 2019 had made at the previous election two years earlier. In fact, according to the 30,000 sample British Election Study internet panel (BESIP), rather more Brexit Party voters had voted Conservative (40%) than Labour (30%) in 2017, suggesting that there was little truth to Mr Farage’s assertion that this party was particularly effective at winning over Labour voters in Labour constituencies. However, what matters here is not how Brexit Party voters voted in 2017, but how they would have voted in the absence of a Brexit Party candidate in 2019.

One way of trying to address this counterfactual question is to compare the performance of the parties where the Brexit Party did and did not stand. At +5.3%, the swing from Labour to Conservative since 2017 was rather higher in seats (In England & Wales) that the Brexit Party contested than it was is those seats that it did not (+4.7%). That suggests that the presence of a Brexit Party candidate did do Labour somewhat more harm than the Conservatives, an observation apparently reinforced by the fact that the swing to the Conservatives tended to be higher the bigger the Brexit Party’ share of the vote.

But if the Brexit Party were winning over Labour voters who would never back the Conservatives, we would anticipate that Labour would have lost support more heavily among Leave voters in seats where the Brexit Party stood than it did in those that it did not. Yet the BESIP data suggest that, if anything, the opposite is true. In seats where the Brexit Party stood, 57% of those who voted Leave in 2016 and Labour in 2017 voted for the party again, compared with just 48% in seats the Brexit Party did not contest. Meanwhile, whereas in those seats the Brexit Party did not contest 39% of Labour Leave voters switched to the Conservatives, in seats where there was a Brexit Party presence only 26% did so. Much of the difference between these two figures is accounted for by the 10% who backed the Brexit Party in seats the party was contesting – suggesting that all the Brexit Party managed to achieve where it stood was to divert the support of Labour Leave voters away from the Conservatives.

This in turn, however, is also probably too bold a conclusion. When the BESIP asked respondents to give both the parties and the leaders a mark out of ten, those Leave voters who switched from Labour to the Brexit Party gave both the Conservatives (3.8) and Boris Johnson (5.3) a lower score than those who switched from Labour to the Conservatives (6.2 and 7.1 respectively), suggesting that perhaps not all of those who switched from Labour to the Brexit Party would have swung behind the Conservatives in the absence of a Brexit Party candidate.

In the absence of data on the second preferences of those who voted for the Brexit Party, we modelled the behaviour of Labour Leave voters in seats that the Brexit Party did not contest (taking into account demographics and evaluations of the parties and leaders) and then applied the resulting equation to those voters who elsewhere switched from Labour to the Brexit Party. This suggested that in the absence of a Brexit Party candidate, 70% of those who switched from Labour to the Brexit Party would have instead backed the Conservatives, while just 30% would have stuck with Labour.

It is on this basis that we conclude that the Brexit Party’s decision to continue to fight opposition held seats cost the Conservatives seats they might otherwise have won. If we apply that 70:30 ratio to the share of the Brexit Party’ share of the vote in each constituency, we find that there are around 25 seats that Labour managed to retain that might otherwise have fallen from its grasp – many of them in the North of England and the Midlands – and enough to give the Conservatives an overall majority of 130.

Meanwhile, because there was a national swing from Labour to the Conservatives anyway, the Brexit Party’s decision to stand down in Conservative-held seats helped save the Conservatives from defeat in at most a small handful of Remain-inclined seats.

The squeeze on Brexit Party support during the 2019 election campaign, a squeeze that was probably accelerated by its decision to vacate the contest in Conservative-held seats, played a role in enabling the Conservatives to unite much of the Leave vote behind it, an outcome that was central to their success in winning an overall majority of 80. Even so, the Brexit Party’s continued presence in seats that the opposition parties were defending still acted as something of a brake on that achievement. Small though its tally of votes might have been, under the first-past-the-post electoral system, it was still enough to make a significant dent in the size of the Conservative majority and in reducing the extent of the breach in Labour’s so-called ‘Red Wall’. Little wonder that, in the wake of the outcome of the Old Bexley & Sidcup by-election, commentators are now wondering what role, if any, the Brexit Party’s successor, Reform UK, might play at the next general election.

This blog is also to be found on the What UK Thinks website.

            The British General Election of 2019, by Robert Ford, Tim Bale, Will Jennings and Paula Surridge is published by Palgrave Macmillan.

Final combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks

Since our first combined forecast at the start of the campaign, the number of forecasts for this general election has grown substantially. All of the combined forecasts – seats, vote shares, and probabilities – are pointing to a Conservative majority. However, some individual forecasts do predict a hung parliament, and there is variation within each forecast type over how certain this majority is, and how large it is predicted to be.


Seat projections from the betting markets, complex models, and simple models are all very similar, forecasting a Conservative majority of between 343 and 351 seats. The average number of seats across all forecasts that the Conservatives are expected to win – 341 – is slightly lower but ultimately very similar to the forecast last week.

Since last week the Political Studies Association have published their Expert Survey, in which the average expected number of Conservative seats suggests a hung parliament with the Conservatives just shy of a majority. It is interesting that the experts surveyed by the PSA predict the Conservatives will win fewer seats than is currently suggested by the polls. Perhaps they are factoring in the same kind of late-campaign changes as observed in 2017 – although it should be noted that when a similar kind of survey was run for the EU referendum in 2016, the average predicted vote share for Remain and Leave amongst experts was the furthest away from the actual result than any of the other types of forecast. They also predicted a Conservative majority in 2017, although that prediction was made much more earlier in the campaign when the Conservatives had considerable leads over Labour in the polls.

Seats Betting Markets Complex models Simple models Experts Average
Con 346 343 350 324 341
Lab 221 225 219 233 224
LD 18 17 18 25 19
Brexit 0 0 0 2 1
Green 1 1 1 2 1
SNP 43 44 41 42 43
PC 4 3 3 4 4
Con majority 42 37 49 -2 31


Conservative Seats - 11th December

The similarity between the seat projections from most sources hides considerable variation within one particular forecast type – complex models. These models range from predicting 311 Conservative seats to 366 – the difference between a hung parliament and a healthy Conservative majority. They also range between 190 and 268 for Labour. It is particularly noteworthy that the voter expectation model, from Murr, Stegmaier, and Lewis-Beck, which uses citizen forecasts to predict the number of seats, forecasts one of the highest number of Conservative seats (360) and the lowest number of Labour seats (190). This is in contrast to our implied probability calculated from the citizen forecasts, which suggest that citizens are in general the least convinced about the likelihood of a Conservative majority compared to other forecasting methods. This suggests these surveys also suffer from being open to multiple interpretations and methods of analysis, as well as the question wording effects we discussed last week.

Continue reading Final combined forecast for the 2019 general election

The 2018 and 2019 local election results suggested the Conservatives might struggle to get a majority at the next general election

By Chris Prosser and Stephen Fisher.

Every May local election results are analysed as indicators of the state of the political parties and scrutinised for what they tell might tell us about the outcome of the next general election. That general election is tomorrow. Although a lot has happened in politics since May 2019, and especially since May 2018, it might be worthwhile reminding ourselves of what happened in the local elections then and what those results portend for the outcome this week.

In 2015, when the polls failed to anticipate a Conservative majority, one of the more successful forecasting models was Chris Prosser’s one based on the 2013 and 2014 rounds of local elections. Unlike the polls – which showed the Conservatives and Labour neck and neck – that model forecast a four point Conservative lead in vote share. Using a uniform change projection, the forecast shares predicted a Conservative tally of 296 seats for 2015, short of an overall majority but better than a uniform projection from the final opinion polls and the best of a set of twelve academic forecasting models for that election.

Applying the same method again, the table below shows that both the 2018 and 2019 rounds of local elections point to a clear lead for the Conservatives in a subsequent general election. However, the forecast shares of the vote from both rounds do not suggest a big enough lead for the Conservatives to be sure of an overall majority. On the average of the two set of vote shares, coupled with a uniform change projection (also using last night’s YouGov MrP projected SNP and PC vote shares) points to a very narrow Conservative majority of 8.

Party Forecast share based on 2018 results Forecast share based on 2019 results Average forecast share Standard Error of share forecast Seats forecast
Con 40.8 36 38.4 4 329
Lab 33.8 29 31.4 4 231
LD 13.4 15.4 14.4 4 23
Other 12 19.6 15.8 4 65

The fact that a forecast based on local elections 7 and 19 months ago should be so close to last night’s YouGov MrP projection of Con 339, Lab 231, LD 15 is remarkable. There is just a difference of 10 seats for the Tories and none for Labour.

Given that since the 2018 local elections we’ve had May’s Deal and the first missed Brexit deadline, and since the 2019 local elections we’ve seen Brexit Party and Lib Dem success in the European parliament elections, a new prime minister, a new Brexit withdrawal agreement, and another missed Brexit deadline, it is even more surprising that most opinion polls now do not differ profoundly from what previous local elections suggested would happen.

The Party Leadership Model predicts a Conservative overall majority

By Andreas Murr and Stephen Fisher.

Two years ago Andrew Adonis wrote a piece in Prospect arguing that Labour should ditch Jeremy Corbyn because of the importance of party leadership for electoral success. The piece claimed that “the best leader wins and nothing else matters,” and in Lord Adonis’s view Mr Corbyn is the worst Labour leader since Michael Foot. So, Adonis concluded already in September 2017, that regarding the next election “Corbyn will lose it decisively if he contests it.”

In response to Adonis’ claims many, including Danny Finkelstein, expressed skepticism about the power of leadership and pointed out that it is difficult to properly evaluate the quality of leaders in retrospect. Once we know who won and who lost we have a tendency to convince ourselves that the winner was a better leader than the loser. But there are ways of producing measures of leadership quality prior to elections which have historically been useful for forecasting election outcome.

The Party Leadership Model, was devised by Andreas Murr in the run up to the 2015 general election. It successfully anticipated David Cameron’s victory unlike the vast majority of other forecasts at the time. Murr has elaborated the model further for this election to produce a seats forecast, not just a prediction as to who will emerge as prime minister. His new model forecasts that the Conservatives will win an overall majority this week with 342 seats, and that Labour will win 254 seats.

Continue reading The Party Leadership Model predicts a Conservative overall majority

Why are polls from different pollsters so different?

By Stephen Fisher and Dan Snow.

On average the polls have had a fairly consistent and comfortable lead for the Conservatives in this general election campaign. However, around that average there are substantial differences between polls. Some suggest the Conservatives might fail to win a big enough lead to secure a majority, while others point to a Tory landslide with a majority over a hundred. What’s going on?

In short, since this is a long and complicated blog, our tentative conclusion is that the big systematic differences between pollsters are due primarily to systematic differences in the kinds of people they have in their samples, even after weighting. Some of the sample profile differences translate straightforwardly into headline differences. For instance, having more 2017 Conservatives in a sample means there will be more 2019 Conservatives. In other areas there are more puzzling findings. Polls vary in the extent to which women are more undecided than men and in the extent to which young adults are less certain to vote, but neither source of variation has the effect on headline figures that we would expect. Nonetheless for most of the aspects of the poll sample profiles we have inspected, it is remarkable the extent to which polls differ primarily between pollsters, with relatively little change over time for each pollster. This suggests that the way different pollsters have been going about collecting responses has yielded systematically different kinds of respondents for different pollsters. With a couple of exceptions, it seems as though it has been the process of data collection rather than post-hoc weighting and adjustment that may be driving pollster differences in this campaign.

As the graph below shows, a large part of the variation between polls is between pollsters. The pollsters have shown a similar pattern of change in the Conservative-Labour lead over time, most with a peak in mid-November and a slight decline since. The headline Conservative-Labour lead – the basis for the swingometer – is the main guide to seat outcomes. So an important question is why pollsters differ systematically in the size of their published Conservative leads.


In this blog post we use data from the standard tables that pollsters have to publish as part of the requirements of British Polling Council membership. They contain a wealth of information about the profiles of the different survey samples both before and after weighting and adjustment. We collected data from such tables for all polls between the 30th of October (when parliament voted for an early general election) to the 4th of December (just over a week before the end of the campaign). There have been more polls since then but so far as we can tell they do not substantially change the issues we raise here.

Continue reading Why are polls from different pollsters so different?

Fifth combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks 

Since our update last week there have been several new forecasts, most notably including the YouGov MRP (multilevel regression and post-stratification) model. That was a nowcast rather than a forecast, but the same is true of most of our “forecasts”. More on differences between forecasting models below, along with some observations about intriguing question wording effects for citizen forecasts.

But first, overall, the seats projections overall have tightened for the Conservatives, who are down from a 353 average last week to 346 this week, while Labour are up from 209 to 218. The Liberal Democrat forecast total has dropped yet again (from 23 to 19). Now they are estimated to return fewer MPs than they had going into the election (20), but still more than the number of seats they won in 2017 (12).

Seats Betting Markets Complex models Simple models Average
Con 343 347 348 346
Lab 220 218 217 218
LD 19 18 19 19
Brexit 0 0 0
Green 1 1 1 1
SNP 45 45 44 45
PC 5 4 3 4
Con majority 36 45 46 42

Conservative Seats - 4th December

There is now remarkably little difference between the betting markets, complex and simple models in the expected size of the Conservative majority. Particularly striking is that on average the complex models differ by only a seat for each party from the simple uniform change projections based on the average of the opinion polls.

Continue reading Fifth combined forecast for the 2019 general election

Fourth combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks 

There has not been much change in our combined forecast over the last week. The Conservatives are still apparently headed towards a comfortable majority (55 on average) based on an average forecast vote share lead over Labour of 12 points. The average predicted probability of a Tory majority has crept up to 72%, partly due to increasing confidence in the betting markets and the quantitative forecasting models, as well as the polls. Citizens remain much more sceptical. Concerns that the Liberal Democrats might make little advance continue, and were compounded by the Datapraxis MrP forecast of just 14 seats for the party. Otherwise the Datapraxis forecast was largely in line with other forecasts of headline seats totals. Further MrP based forecasts are due this week, including YouGov’s.

Seats Betting Markets Complex models Simple models Average
Con 346 353 360 353
Lab 210 212 204 209
LD 25 21 22 23
Brexit 0 0 0
Green 1 1 1 1
SNP 45 45 43 44
PC 4 4 4 4
Con majority 42 55 69 55

Conservative Seats - 27th November   Continue reading Fourth combined forecast for the 2019 general election

Third combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks 

Once again all three sources of seat forecasts suggest the Conservatives are heading to a comfortable majority, while Labour are on course for a result on par with their previous post-war low of 209 seats in 1983. The Liberal Democrat forecast has been dropping steadily, so that they are now expected to end up with only a few more MPs than the twenty they had when they chose to support the election.

Seats Betting Markets Complex models Simple models Average
Con 346 354 363 354
Lab 209 211 200 206
LD 30 22 22 25
Brexit 0 0 0
Green 2 1 1 1
SNP 46 46 44 45
PC 4 4 4 4
Con majority 42 58 75 58

Con seats 20 NovLib Dem seats 20 Nov 

Continue reading Third combined forecast for the 2019 general election

Second combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks

There are still just a few different forecasts for the general election. Perhaps the big changes during the 2017 campaign have made people more hesitant about predicting early this time. Perhaps the problems of the polls in 2015, 2016 and 2017 have put some off the idea entirely. (More on this in our post-mortem for the 2017 combined forecast which we’re still working on.) Nonetheless, this is the second of our weekly blogs where we review the different forecasts from different methods and combine them into an overall forecast.

Here we aggregate seats and vote share forecasts from a variety of sources including betting markets, polls, statistical forecasting models and citizen forecasts. As well as updating weekly, the methodology (as detailed below) might well evolve. So comments and suggestions on our approach and for new forecasts to include are welcome.

Just as they did last week, all the different sources point to the Conservatives being comfortably the largest party, with heavy losses for Labour and modest gains for the Liberal Democrats and Scottish National Party (SNP). Last week the betting markets suggested a smaller Tory tally than did the forecasting models. The models haven’t changed much but the betting markets have moved into line with forecasts. On average across betting markets, and complex and simple models, the Tories are expected to win with a comfortable majority of 60, barely changed from 57 last week. All three sources now suggest a majority of 50 or more.

Seats Betting Markets Complex models Simple models Average
Con 352 360 353 355
Lab 210 201 193 201
LD 37 25 30 31
Brexit 0 0 0
Green 2 1 1 1
SNP 46 48 50 48
PC 5 4 4 4
Con majority 54 70 56 60

Conservative Seats - 13th Nov

Continue reading Second combined forecast for the 2019 general election

First combined forecast for the 2019 general election

By Stephen Fisher, John Kenny and Rosalind Shorrocks (Universities of Oxford, Southampton and Manchester respectively)

There aren’t so many different forecasts for the general election out yet, but enough to start looking at how they compare. This is the first of hopefully weekly blogs where we review the different forecasts from different methods and combine them into an overall forecast. At the moment, the polls and seats forecasts suggest a comfortable Conservative majority but citizens and betting markets are not so sure it will happen.

The idea of combining forecasts from different sources has a good track record, though it has to be admitted that our attempts for the 2017 general election and the 2016 Brexit referendum did not work out well. We will write more about those experiences soon. Also worth noting is the experience of the combined forecast of the US presidential elections.

Here we aggregate seats and vote share forecasts from a variety of sources including betting markets, polls, statistical forecasting models and citizen forecasts. As well as updating weekly, the methodology (as detailed below) might well evolve. So comments and suggestions on our approach and for new forecasts to include are welcome.

Continue reading First combined forecast for the 2019 general election