UPDATE – YouGov puts him 6% behind?

[UPDATE I wrote this article before getting news of a new YouGov poll on the mayor race which has Ken leading Boris 45-39% on first preferences and 53-47% after second. This is probably better than the Tories would have expected at this stage and clearly everything will depend on turnout levels]

The Tories have not got a good record when it has come to finding someone suitable to fight Britain’s biggest election – the four yearly contest for mayor of London where there’s a single electorate of millions.

Their first selection ahead of the 2000 race was Lord Archer who ran into a “spot of bother”. He was replaced by Steve Norris who hammered the official Labour candidate and came second to Livingstone. Norris’s 2004 bid against Ken, who had been readmitted to Labour in spite of Brown, was plagued by his links with Jarvis just as rail safety became a mega-issue.

Now they’ve got Boris who has a high public profile but is vulnerable to being portrayed as the loveable baffoon from TV comedy shows.

On the face of it Johnson should be looking at 2008 with some confidence – the Tories are riding high in the polls and the electoral system gives them a unique advantage over Labour. For the Mayor is elected by taking the aggregate of votes across London meaning that Tory areas, where there are high turnouts, have disproportionately more impact on the outcome than the Labour areas where turnout levels are lower.

Alas it has not worked like that. By comparing the London Authority results, where the voting takes place at the same time, it’s clear that large numbers of Tory voters, about one in six, were prepared to switch to Ken’s Labour in the mayoral election.

So a key task for the Tories is to stop the seepage and to pick up second preferences from the Lib Dems and the plethora of other candidates that are likely to be running.

Ken has carefully crafted himself into a brand that is above party and it is hard to see what Johnson can do.

He might find the “baffoon” tag to be less damaging than Norris’s “Jarvis” but my guess is that enough Tory voters will go for Ken to give him a third term.

For Dave the promlem is that however well the Tories do in next May’s local elections it will be this London result that makes the headlines.

Mike Smithson