Will this increase the nervousness amongst MPs in the marginals?

The pollster which has been operating in the UK for longer than anybody else has just published their Monitor for July 2008 and it shows a move towards the Conservatives and the biggest lead for the party in decades.

These are the figures with comparisons on a month ago CON 47% (+2): LAB 27% (-2): LD 15% (-2). These figures, like all MORI surveys are based on those “certain to vote”. The fieldwork ended on July 20th – so it’s up to date.

The pollster which is the only one that does not applying a political weighting to its samples. has undergone a major methodological review which took place following the London Mayoral election. All surveys are now done by telephone and the pollster takes measures to ensure that it is not over-representing public sector workers in its samples

These latest findings mean that that two of the five firms – ICM and Populus – that regularly survey GB voting intentions have shown a narrowing of the gap over Labour while the other three – MORI, ComRes and YouGov – are reporting the opposite effect.

There was a marked move away from the Conservatives on the spread betting commons seats markets following the ICM Guardian poll on Monday night that showed that the gap was narrowing. Will this change that?

By-election betting – live latest prices

Mike Smithson