For months, the conventional wisdom was that the London mayoral race is already called for the Tories. But the polls tell a different story. Ken Livingstone and Boris Johnson are neck and neck, in what is shaping up to be London's closest mayoral contest since devolved government was reintroduced in the capital.

Boris may have regained the lead, but YouGov puts only two points between them, and according to reports today, Tory top command is starting to worry.

Alice Thompson writes in the Times (£):

Downing Street is worried. When the mayor came in with his Australian election strategist Lynton Crosby last week, they thought their plans were "underwhelming" and lacked a simple "retail offer" for voters. Boris might irritate the Prime Minister but the Conservatives need him to stay in City Hall. They are even prepared to consider Boris Island, his plan for a new airport, if it helps his cause.

The fundamental problem appears to be that his campaign lacks direction. According to Thompson's report, internal Tory polling shows that voters can't see what Boris has done. Ken has a clear "retail offer": cutting fares and bashing bankers. Boris's campaign, meanwhile, lacks direction, while his association with the City continues to be a problem.

He has always been a politician who relies on personality. Last month my colleague Rafael Behr argued that Boris's incumbency might be hurting this trump card:

Last time around, Boris was the challenger, which suited his self-image as a bit of a maverick, an eccentric, a TV personality and so, crucially, not a typical Tory. Some of that image remains, but the mantle of office has necessarily imposed a degree of discipline on the mayor. He still gets away with more mannered dishevelment than is usual for someone in his position, but there is an extent to which his pre-election persona has been absorbed into a more conventional political identity. Or, to put it in cruder terms, he is becoming more Tory than Boris.

Thompson quotes an aide saying that "Boris needs a fright" and that a close race will be good for him. Which way the vote goes on 3 May depends on many factors, not least voter turnout, but there is certainly a lot at more at stake than the cartoon rivalry between two big personalities. A win for Ken -- widely seen as past his political prime -- would be a serious mid-term shock for the Tories. It is no surprise that Downing Street is rearing into action.