The man leading an independent review into the future of Britain's airports has called on Boris Johnson to stop politicising the debate over how the country should expand its aviation capacity.
Sir Howard Davies, chair of the Government-ordered Airports Commission, said his inquiry needed to focus on the issues surrounding whether and where to build the UK's next major air hub rather than the timing and politics.
His comments came after the London mayor threatened to undermine the three-year review by complaining the process was too slow and publicly dismissing the option of a third runway at Heathrow.
Former Financial Services Authority chief Sir Howard said he was determined to ignore the "swirling" political row over the issue and insisted that the option of expanding the UK's largest airport will "stay on the table".
He told The Observer: "Obviously we have to have a public process here, but the public process I want is about the issues rather than about the timing and the politics. I don't think we can afford them (the politics) to be (involved), quite frankly. I think the whole point of asking an independent commission to do this is in order not to do that."
Sir Howard, who launched the commission on Friday, added: "I observe the political debate swirling around this, but I don't think it makes sense to get involved in it. We have been told that all options, including the third runway, are on the table, and for the moment that is where they shall remain."
The former mandarin, who admitted that he "can't be convinced" politicians will actually listen to the aviation commission's final report when it is published in 2015, followed in the footsteps of David Cameron in rebuking Mr Johnson's comments.
The Prime Minister insisted the mayor was wrong to dismiss the option of a third runway at Heathrow and would not be given a veto on the critical issue.
"In the end the decision is a national decision that the Government has to lead," Mr Cameron told The Times. "What is not right is to say, I only want my options considered and not anyone else's."
Mr Johnson - who favours a new airport in the Thames Estuary - said the inquiry should not be considering another runway at Heathrow because the idea was "a complete disaster" and "simply will not happen". He warned that the Tories would suffer if they had not ruled out the controversial move before the next general election.