Vote 2010: today's election barometer
Updated on 15 April 2010
The Conservatives shore up their lead in the opinion polls ahead of this evening's crucial leaders' debate. Professor Leighton Vaughan Williams, of Nottingham Business School's Political Forecasting Unit, looks at the latest polling figures.
The latest polls show the Conservatives shoring up their poll lead, but there is little change in the broad picture, with the Conservative percentage vote share in the upper 30s, Labour in the lower 30s and the Liberal Democrats at or around 20 per cent.
The markets continue to point to a small Tory majority, of 6 seats, unchanged from yesterday.
The Political Forecasting Unit 'Polling Tracker' has the Conservatives seven points ahead of Labour.
Reproduced as a uniform swing across the country, this would put both the Conservatives on 294 seats and Labour on 275 seats, which would make the projected 51 seats for the Liberal Democrats critical to securing a majority in the House of Commons.
Polling Commentary
There are two current national polls out today.
ComRes/ITV/Independent: Con 35, Lab 29, LD 21
YouGov/Sun: Con 41, Lab 32, LD 18
A big difference here is in the vote share for 'others' (i.e. not Con, Lab or Lib Dem), which comes in at 15 per cent for ComRes, but just nine per cent for YouGov.
Can it be explained because YouGov is an online pollster, while ComRes interview by telephone? Is it because the polling organisations took their samples at slightly different times? Perhaps it's the way that 'don't knows' are classified? Time may tell.
There is one other national poll, by Harris for the Metro, but the fieldwork took place between last Thursday 8 April and Tuesday 13 April , and so is not included in today's Poll of Polls.
For information, this gives the Conservatives 36 per cent, Labour 27 per cent and the Liberal Democrats 23 per cent.
A poll of 100 key marginals by Crosby/Textor is reported in today's Daily Telegraph to show the Conservatives picking up 74 Labour seats but none of the 20 Liberal Democrat seats in the sample.
The reported swing from Labour to the Conservatives since 2005 is of six per cent. This is consistent with the state of the parties in the marginals being within a point or so of where they stand in today's national 'Polls of Polls' and 'Polling Tracker.'
This is quite a small divergence, and for what it's worth suggests that the Conservatives are doing at least as well in the marginals as the country as a whole, but not much better.
Political Forecasting Unit's (PFU) "polling tracker" gives the same picture.
Put simply, the tracker is based on the most recent surveys by different polling organisations, and is adjusted so that the more recent the survey the more weight is attached to the vote shares. There is also some statistical smoothing which has the effect that outliers or vote shares that diverge most from the general consensus are allocated less weight.
Election barometer
The Political Forecasting Unit's 'election barometer', designed to capture the changing state of the race as it unfolds through the campaign, also shows the Conservatives falling short of an overall majority based on the recent polling, assuming a uniform national swing.
But an analysis of the money bet in political betting markets currently translates into a Conservative overall majority of 6, unchanged from yesterday.
Daily poll of polls
Conservative: 38 per cent
Labour: 31 per cent
Liberal Democrat: 20 per cent
PFU polling tracker (recent polls, weighted)
Conservative: 38 per cent
Labour: 31 per cent
Liberal Democrat: 20 per cent
Outcome (Based on polling tracker, assuming national swing reproduced in every constituency)
Conservatives: 294 seats
Labour: 275 seats
Liberal Democrat: 51 seats
Other: 30 seats
Conservatives short of an overall majority by 32.
Where the money is (Analysis based on money wagered on the election in political betting markets)
Conservative: 328 seats
Labour: 226 seats
Liberal Democrat: 62 seats
Translates into a Conservative overall majority of 6
% chance of Conservative overall majority: 57.6 per cent
% chance of No overall majority: 36.3 per cent
% chance of Labour overall majority: 6.0 per cent
(Chances based on odds from betting exchanges)
Professor Leighton Vaughan Williams is Director of the Political Forecasting Unit at Nottingham Business School.
