Posted by Chris Gilson and Patrick Dunleavy.

Latest Poll Information for 26 March

All the recent polls have shown a narrowing of the gap between the Conservatives and Labour. As the recent Hicks-Vivyan analysis on this Blog shows, the Conservatives’ support has drifted down perilously close to the magic number of 35 per cent where the Tory-Labour vote would be evenly balanced (assuming that the Liberal Democrats get around 20 per cent and others around 10 per cent, as all recent polls suggest). The most recent YouGov poll puts the Tories on 36 per cent and Labour on 34, the smallest gap yet recorded since early 2009. Little wonder then that yesterday’s Evening Standard reported that the Tories have asked the Saatchi brothers advertising firm to help relaunch their apparently flagging campaign.

In our measure today, Labour recovers from its low of 30 points on Wednesday to 33 points today, but is still a tantalizing 2-3 per cent below the level that it got in 2005, and which might well ensure Gordon Brown’s ability to continue in office, albeit this time heading a coalition or minority government in a hung Parliament. It will be interesting to see if Alastair Darling’s budget pushes the government’s ratings up or down (as his previous efforts have). The BBC’s most recent poll is the IpsosMORI poll of earlier this week, and its score actually reflects our scores from Wednesday.

Turning to the consequences of all this for the House of Commons, the Table below shows that applying a simple uniform national swing would predict a result on the border of what we elsewhere call a deeply hung Parliament, but with Labour and not the Conservatives receiving most seats and thus able to form a government. Here a coalition government pact would almost certainly be needed for British government to function effectively. (Labour needs more seats to get to a shallow hung Parliament, because it must offset unionist MPs from Northern Ireland). The latest seats projection from UK Polling Report also agrees that we are heading for a deeply hung Parliament, but they predict the two parties having essentially the same number of MPs, making it every difficult to see who should form the government.

Seat Projections for 26 March

(Notes: *In projecting seats, we assume that the Liberal Democrats will poll 2 per cent higher and ‘Others’ 2 per cent lower on polling day, in line with previous general elections.)

However, there is a high likelihood that in fact a uniform national swing picture will not apply, and that the Conservatives will do better in gaining votes in marginal seats than they do nationally. The most recent projection by LSE analysts Professor Simon Hix  and Nick Vivyan uses a more sophisticated model of constituency behaviours, allowing for the Tories having greater success in marginal seats. Their projection essentially gives the Tories 40+ more seats at Labour’s expense than a uniform national swing. Hence they predict a shallow hung Parliament with David Cameron heading a minority government for a year, probably entailing a second general election in May 2011. Their view is closely backed by the Electoral Calculus seats projection.

Yet what our Table dramatically captures is how narrow a margin now separates one outcome and future pathway for British democracy from another. As ever with our highly disproportional and erratic voting system, tiny changes in support may map out on the ground as very different results.