Liberal Democrat MP Lembit Opik says he has no intention of standing to be the party's candidate for mayor of London.
Lembit Opik, at a recent event with the Cheeky Girls pop duo
Ed Davey, Lib Dem leader Sir Menzies Campbell's chief of staff, prompted the speculation after saying he thought that Mr Opik would make a good mayor.
The Montgomeryshire MP, best known for dating one of the Cheeky Girls, replied that he was "flattered... me, Boris and Ken would be a splendid contest".
But he later told the BBC that he had decided against entering the race.
The idea of Mr Opik standing was initially put to Mr Davey in an interview with ePolitix.com.
Mr Davey said: "Lembit is a good friend of mine, I share an office with him, and if he decided to run he would certainly make one of the most interesting candidates in the race.
"Would Lembit make a good mayor? I think that Lembit would make a much better mayor than Boris Johnson or Ken Livingstone."
Later, Mr Opik said: "It's ever so flattering. If I was a London MP I would stand like a shot. The only issue is my constituency is 205 miles away.
"I think I might go and have a chat with the boss to see what's going on. The momentum seems to be developing a life of its own."
Boris Johnson is likely to be the Conservative Party candidate
Mr Opik, who has been Lib Dem spokesman on Northern Ireland and Wales, and is currently spokesman on business, has had a long-term interest in the risk to Earth from meteorites.
But he has filled many tabloid pages over the past year as a result of the ending of his engagement to weather presenter Sian Lloyd and subsequent relationship with Gabriela Irimia from the Cheeky Girls.
If he were to enter the race the Lib Dems are drawing up a shortlist in September with a final choice expected later in the year.
However he later told the BBC that he did not want to enter the London mayoral race.
He said he was "very flattered by the outpouring of affection" to convince him to run, but his first priority was to his Mid-Wales constituency
He pointed out with his work as the Liberal Democrats' business and enterprise spokesman, and as MP for Montgomeryshire, meant he did not think he "can fit in running the capital".
Current mayor Mr Livingstone famously won his first term as an independent after being expelled from the Labour Party.
He has since rejoined Labour and won his second term as the official Labour candidate and is to stand again next year as the Labour candidate.
The Conservatives have yet to decide on their candidate, but the well-known ex-Spectator editor and Tory MP Boris Johnson is the favourite to win the race to be their candidate.
Mr Johnson now faces a Tory selection process including open primaries where any Londoner on the electoral register can vote.
The others on the shortlist are Andrew Boff, Victoria Borwick and Warwick Lightfoot - all party activists.