This is the first of our forecasts for the UK General Election in 2015. To see our methodology click here.
Forecast
Our mid point and confidence interval forecast for seats is as follows.
| Party | Seats – Mid Point | Seats 50% CI | Seats 95% CI |
| Conservatives | 324 | 318 – 328 | 306 – 335 |
| Labour | 268 | 259 – 274 | 245 – 282 |
| Liberal Democrats | 14 | 12 – 19 | 7 – 27 |
| UKIP | 1 | 0 – 7 | 0 – 25 |
| SNP | 13 | 12 – 15 | 11 – 18 |
| PC | 4 | 4 | 4 |
| Others inc. Green (GB) | 4 | 3 – 4 | 1 – 4 |
| Irish | 18 | n/a | n/a |
Our mid point and confidence interval forecast for votes (mainland GB) is as follows.
| Party | Vote% – Mid Point | Vote% 50% CI | Vote% 95% CI |
| Conservatives | 34.5 | 33.6 – 35.4 | 31.8 – 36.9 |
| Labour | 28.9 | 27.5 – 30.4 | 24.9 – 32.8 |
| Liberal Democrats | 14.8 | 14.0 – 15.5 | 12.6 – 16.9 |
| UKIP | 13.5 | 11.9 – 15.1 | 8.9 – 17.0 |
Our probability of different outcomes is as follows.
What are the main points of your forecast?
We identify the following events
- Although the Conservative lose seats to Labour, they more than make up for this in gaining seats from the Liberal Democrats
- The SNP are set to at least double their seats in Scotland. If they maintain their current poll rating up to the General Election (at the moment we are expecting the SNP support to fall back in the next few months) we expect them to even outperform Labour on polling day.
- UKIP are on the cusp of a level of support which, in scenarios with a poor Conservative turnout, could see them winning up to 20 seats.
Why is your forecast different to that of Stephen Fisher?
We use the same fundamental forecasting principle as Professor Stephen Fisher with the following crucial differences.
- We use a different sample of elections to model movement of party support prior to a national vote
- We specifically model UKIP support and do some additional local analysis on where UKIP might do well
- We have regional models which help to capture specific local peculiarities (for example, we model Scotland independent of the rest of Great Britain, allowing us to capture the current spike in support for the SNP – Stephen Fisher currently does not do this).
- We have used some components of this methodology before and that allows us to make corrections as we compare our outcome to real results.
This is a very different prediction from Fisher’s!
Are you forecasting the Rochester by-election?
I may have a go.
Yes, it’s different to Fisher, but I’m already doing some of the things he’s thinking about doing. This is a very hard election to predict because the impact of UKIP is uncertain. That’s what leads to my large 95% CI for their seat tally.