Forecast update: 6 February 2015

Forecast main 150206

Despite the noise of individual polls, our national polling average has been steady for a while now: it’s been Labour 33%, Conservatives 32% for five consecutive weeks.

In a sense, the lack of movement is bad news for both parties, as each look less and less likely of being able to pull ahead sufficiently to win a majority in May. The chances of a Hung Parliament have risen from 79% when we launched our new forecasting method three weeks ago to 85% now.

In another sense, it’s worse news for the Tories, as our model expects them to gain and Labour to fall back. Every week that doesn’t happen, their position in our forecast weakens slightly. (This effect is very small over three weeks though: our forecast for national vote shares has gone from Con 34.0%, Lab 31.2% to Con 33.8%, Lab 31.3%.)

However, that’s been more than offset by the SNP’s rise in Scotland hurting Labour. They’ve risen by another point in our central forecast this week, so we now expect them to beat Labour 44%-30% north of the border, enough for them to win around 41 seats (compared to the six they currently hold).

All this means that the Conservatives are still clear favourites to win the most votes (with a 70% chance) and slight favourites to win the most seats (with a 52% chance), but underdogs when it comes to holding on to Number 10.

While Ed Miliband only has a 5% chance of winning an outright majority to David Cameron’s 10%, he has much more scope to cobble together enough support to allow him to lead a coalition or minority government – mainly because of the SNP, who have ruled out supporting a Tory-led government.


Date of forecast: 6 February 2015
Days till the election: 90

Inputted current average poll shares
Con: 32%
Lab: 33%
LD: 8%
UKIP: 15%
Others: 12%

Forecast GB Vote Shares (with 95% Prediction Intervals)
Con: 33.8% (±5, i.e. 29% – 38%)
Lab: 31.3% (±5, i.e. 27% – 36%)
LD: 10.3% (±5, i.e. 6% – 15%)
UKIP: 13.7% (±5, i.e. 9% – 18%)
Others: 10.9% (±2, i.e. 9% – 13%)

Forecast Scotland Vote Shares (with 95% Prediction Intervals)
SNP: 44% (±5, i.e. 39% – 49%)
Labour: 30% (±5, i.e. 25% – 35%)

Forecast GB Seats (with 95% Prediction Intervals)
Con: 282 (234 – 335)
Lab: 279 (229 – 324)
LD: 23 (13 – 36)
SNP: 41 (28 – 51)
PC: 3
Grn: 1
(May not sum to 632 due to rounding of sums of probabilities. Prediction intervals not yet available for UKIP, PC and Grn.)

Central forecast: Con largest party, but short of a majority by 41
(Criterion for majority now changed to 323 not 326, assuming Sinn Fein win 5 seats and do not take them.)

Probabilities of key outcomes
Con largest: 52%
Lab largest: 48%
Hung Parliament: 85%
… with Con largest: 42%
… with Lab largest: 43%

Probabilities of predicted government outcomes:
(See here for explanations and assumptions)

Con majority: 10%
Con+NDown: 0.5%
Con+ND+DUP: 6%
Con+ND+LD: 9%
… with Con+ND+DUP also possible: 6%
… without Con+ND+DUP also possible: 3%

Lab majority: 5%
Left (Lab+SDLP+PC+Grn): 3%
Left+LD: 25%
… with LD as kingmakers: 0.5%
… without LD as kingmakers: 25%
Left+SNP: 46%
… with Left+LD also possible: 25%
… without Left+LD possible: 21%
Left+SNP+LD: 25.5%
… with LD as kingmakers: 24.5%
… without LD as kingmakers: 1%

LD kingmakers: 25%
With a choice between Con+ND+DUP(+UKIP)+LD or
…Lab+SDLP+PC+Grn+LD: 0.5%
…Lab+SDLP+PC+Grn+SNP+LD: 24.5%

(Probabilities may not sum due to rounding)

4 thoughts on “Forecast update: 6 February 2015”

  1. Hello
    Love your site and use if in teaching ALevel Politics in NIreland. Just wondering, you have North Down MP as being pro Tory in your data analysis above. She’s pro Labour(generally) and left the UUP to become and Independent due to the Tory/ UUP pact in 2010. Unless her politics have changed recently? This 1 seat could make all the difference in this tight election although she is a Unionist at heart so I suppose unlikely to be happy with SNP coalition with Labour.
    Just an observation. Keep blogging and posting. This is a great site.

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