Date of forecast: 7 May 2015
Days till the election: It’s today! (Go vote!)

Inputted current average poll shares
Con: 34%
Lab: 33%
LD: 9%
UKIP: 13%
Others: 11%

Forecast GB Vote Shares (with 95% Prediction Intervals)
Con: 35% (31% – 39%)
Lab: 32% (28% – 36%)
LD: 10% (7% – 14%)
UKIP: 12% (8% – 16%)
Others: 11% (9% – 12%)

Forecast Scotland Vote Shares (with 95% Prediction Intervals)
SNP: 48% (44% – 52%)
Labour: 27% (23% – 31%)

Forecast GB Seats (with 95% Prediction Intervals)
Con: 285 (245 – 326)
Lab: 262 (223 – 300)
LD: 25 (17 – 33)
SNP: 53 (45 – 57)
PC: 3 (2 – 3)
UKIP: 3 (3 – 4)
Grn: 1
Other: 1
(May not sum to 632 due to rounding of sums of probabilities.)

Central forecast: Con short of a majority by 38
(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 most votes: 77%
Lab most votes: 23%

Con most seats: 68%
Lab most seats: 32%

Hung Parliament: 94%
… with Con largest: 62%
… with Lab largest: 32%

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

Con majority: 6%
Con+DUP: 5%
Con+LD: 16%
Con+LD+DUP: 14%
Con largest, Lab+SNP+DUP+other left maj: 5%
Con largest, but Lab+SNP+other left maj: 15%
Con largest, but Lab+SNP maj: 6%
Lab largest, Lab+SNP maj: 8%
Lab+LD+DUP+SDLP+PC+Grn+Hermon: 9%
Lab+LD+DUP: 7%
Lab+LD: 7%
Lab+DUP: 1%
Lab majority: 0%

(Probabilities may not sum due to rounding)