London Mayor Boris Johnson has accused David Cameron of a "fudge-arama" over Heathrow, as the row over a third runway overshadowed the completion of the Prime Minister's first full-scale ministerial reshuffle.
At the first meeting of his reshaped Cabinet in Downing Street, Mr Cameron told ministers that he wanted every Government department to focus on economic growth.
He also indicated that he would seek all-party involvement in a commission to review the future provision of airport capacity in the south-east of England, which will hear representations from those arguing for a third runway at Heathrow.
Unconfirmed reports suggested that the commission, which may not report until after the general election, would be chaired by former head of the Financial Services Authority Sir Howard Davies.
Mr Cameron said that he would not ditch his manifesto pledge - repeated in the coalition agreement of 2010 - not to expand the west London airport during the course of this Parliament, despite business clamour for more flights. He told MPs: "While I believe we need to establish a form of review that will bring parties together and make a decision about airport capacity, I will not be breaking my manifesto pledge."
But Mr Johnson urged him to go further and take the third runway off the table altogether for the period beyond the 2015 election, warning he would lead a campaign against the proposal if it was revived.
The London Mayor said he feared there was a "stealthy U-turn" under way, backed by Chancellor George Osborne, and described Mr Cameron's proposed consultation process as "just a fudge-arama and just an excuse for delay".
"If such a commission were not to report until after the next election we'd have lost a huge amount of time," said the Mayor, who is calling for a new airport on an artificial island in the Thames estuary. "I don't think British business would be remotely satisfied with that answer."
Asked if he would lead a campaign against expansion at Heathrow, Mr Johnson told BBC Radio 4's World at One: "You bet I will, yes."
Labour, which has been calling for a cross-party commission on airport capacity for a year, accused Mr Cameron of "dither and delay". Sources said leader Ed Miliband was "sceptical" about the case for Heathrow expansion, but ready to consider the terms of reference for the proposed review.