CONSERVATIVES 40% (-5)
LABOUR 37% (+7)
LIB DEMS 12% (-2)

Could this increase the chances of a 2009 election?

MORI has just sent me the headline figures which appear above and have confirmed to me that the shares relate to those who are 100% certain to vote.

This is a sensational poll for Labour and there can be little doubt that it will step up the pressure for an early election.

One thing is clear – MORI is living up to its reputation for great turbulence. In September it had a 28% Tory lead. In October it was down to 15% and today we have it at 3%.

My guess is that when we look at the detail the main driver behind the change be a sharp increase in the certainty to vote responses from Labour voters.

MORI is the only pollster not to use past vote weighting – but it does weight by those who work in the public sector and this has the effect of reducing the Labour and Lib Dem shares.

The MORI voting intention question is, in common with all the pollsters other than ICM, unfriendly to the Lib Dems.

The fieldwork was carried out from 14-16 November 2008. So it started on Friday and went through until Sunday – so it’s very up to date.

UPDATE: I’ve been in contact with MORI who tell me that when they saw the initial figures they did some additional checks. The past vote figures are basically identical to last month’s (ie. MORI haven’t inadvertently over-sampled Labour supporters) and they also had a look at newspaper weights, and they had no effect (readership figures are normal). These tests and a few more satisfied them that the data is accurate.

Mike Smithson