Boris Johnson has dismissed suggestions that he is involved in a plot to oust David Cameron as "cloud cuckoo land".
The mayor of London has been forced to deny reports that Tory MP Zac Goldsmith, who is strongly opposed to the expansion of Heathrow, offered to quit his Richmond seat to allow Johnson to stand in his place, and make a dramatic return to parliament.
"Of course I’ve had conversations with Zac and with other MPs in London and elsewhere about how to solve the aviation problem," Johnson told LBC radio on Monday morning.
But he added: "I’m absolutely not going to be returning to parliament, I’ve got to do a job here in London and that’s what I want to do and it’s a massive, engrossing job."
Johnson has stepped up his war of words with the prime minister in recent days over suggestions that the government is planning to U-turn on its pledge not to expand Heathrow.
The mayor is opposed to the construction of a third runway in West London and instead favours the construction of a new airport in the Thames Estuary to the east of the capital.
The coalition has said its review into the expansion on airport capacity will report back in the summer of 2015, a review Boris has dismissed as a "fudge-arama".
On Monday the Daily Telegraph reported that the mayor intends to conduct his own inquiry which will rule out a third runway at Heathrow and will report back sooner.
On Sunday Tory backbencher Colonel Bob Stewart confirmed he had been approached by two party colleagues before the summer recess asking him to mount a "stalking horse" leadership challenge against Cameron.
Stewart said he rejected the idea and remained loyal to the prime minister. "It was a silly suggestion that I dismissed. I told them to get lost," he said.
Any rebel plot would not be intended to install Stewart as the new leader, but rather use him as a mechanism to spark a leadership contest on behalf of someone else.
Tory MP Stewart Jackson said Cameron's inner circle would be "hating" the speculation about Boris even though it was unlikely he was about to quit City Hall.
"It's a silly season kite flier but speaks of a bigger malaise re Dave," he said on Twitter.