CON 42 (+4) LAB 24 (+1) LD 18 (-4)

But was it more than just the “Norwich Effect”?

This clearly is a very good poll for the Tories who are back in the 40s after five consecutive surveys from the pollster that had them below the magical 40 number including one where they had slumped to just 30%.

The field-work started on Friday and went through to Sunday when the party, and particularly Cameron, was getting a lot of favourable coverage in the media following the capture of Norwich North.

The evidence from past by elections is that polls taken in the immediate aftermath tend to give a boost to the party’s that’s done best.

Whatever – the opening of the gap to 18 points with Labour still in the low 20s – will add further to the gloom at Brown Central which had pinned its hopes on a strong Tory cuts message.

Andrew Hawkins, CEO of ComRes, believes that the Tory strategy of stressing the need for spending cuts in the face of the economic crisis is what is chiming with the public.

The party that will be most disappointed are the Lib Dems who see a sharp reverse on the numbers in the last ComRes poll just ten days ago. So we are getting a mixed picture with Clegg’s party at the moment. The latest YouGov survey had them their highest level for nearly a year.

As regulars will know I have written on a number of occasions about the ComRes weighting system. There have been changes in the past month and these have answered my concerns.

The next poll should be YouGov for the Telegraph at the weekend.

Mike Smithson