With just over four weeks to go before the London Mayoral election Politicalbetting.com’s longstanding call to back Norris looks even better than ever. A You Gov poll in the Evening Standard has the split at Livingstone 40 – Norris 31.

But taking only those saying they are “certain to vote” the figures change to 39-34 a lead for Ken of just 5%

As we’ve been saying for months – this is the best political bet there is. Get on before the prices move down. Those who’ve been backing Ken at 1.2 and laying Norris at 11 on Betfair will soon realise what a mess they are in and they will try to bail themselves out.

What makes uncomfortable reading for them is that Livingstone supporters have a proven history of over-stating their support to pollsters. The opinion polls last time gave him leads over Norris ranging from 57% down to 34% in the final week. It was actually 11.9%.

Four years ago Ken’s margin over Norris was 23% less than his worst opinion poll rating.

There’s no consolation for Ken backers from the second preferences. Last time there were Frank Dobson 2nd prefs to add to his total which won’t be there this time. He’ll still get the Green second votes but Norris will get the most Lib Dem 2nd prefs as well as those from UKIP and BNP voters.

This election will be a good test for YouGov’s methodology. Last time ICM got it wildly wrong because those interviewed were giving them wrong information about their intention to actually vote. YouGov put a series of questions to establish the turnout intention and do not appear to compile their figure on the basis of one answer alone.

Our view that Livingstone was in trouble came from a YouGov poll before Christmas – just as his move to Labour was being made public. That poll put a series of questions and it was clear that as people thought about the issue the less well they were disposed to Ken.

YouGov’s “Gordon Brown” Poll
The full details of Sunday’s national poll has now been published and it does not make good reading for the Liberal Democrats. This had the the CON-LAB split at 40-36 with Tony Blair as leader. If Gordon Brown was in the job the split changed to CON39 – LAB 39. The change came from a Lib Dem reduction of 18% to 16%.

The rating for how well Blair is doing is minus 22; Michael Howard as Tory leader is plus 28; and Charlie Kennedy as LibDem leader is plus 14.