"At the moment, I don't want to be prime minister." After emerging as the big political winner from the Olympics, it's little surprise that Boris Johnson is hedging his bets. Speaking on ITV's Daybreak this morning, he mischievously added: "How could anybody elect a prat who gets stuck in a zip wire? How on earth could you elect that guy?", fully aware that his endearing gaffes are an essential part of his appeal.

Elsewhere, he again noted: "I have got four years of mayor of London ahead". Yet, as I've noted before, there is no constitutional obstacle to him becoming an MP in 2015 while remaining Mayor until 2016. Indeed, there is a precedent. After the 2000 mayoral election, Ken Livingstone remained the MP for Brent East until 2001. As one senior Conservative told the Independent earlier this year:

He could not wear two hats for a long period but doing it for 12 months would not cause a great controversy. Tory associations in London and the Home Counties would queue up to have him as their candidate. He would say he was representing London in Parliament for a year.

It is notable that the Mayor has never publicly ruled out becoming an MP while remaining Mayor of London. When questioned on the subject by Prospect magazine, he "declined to comment but gave a low laugh."

As Cameron's political fortunes continue to decline, it is notable that a growing number of Labour figures now view Boris as the primary threat to their party's hopes of a sustained period in government. The ferocity with which Jacqui Smith denounces the Mayor in her Progress blog (declaring that "people should not be taken in" by him) is evidence of what the party sees as a need to puncture the Boris myth now.