George Osbourne is secretly pushing for a third runway at Heathrow airport, overturning a Conservative manifesto promise made in 2010.
The Independent on Sunday reports that the Chancellor has persuaded David Cameron to reconsider expansion at Heathrow because he feels that it is essential to Britain's 'hub status' for flights between Asia and the Americas.
Deputy Prime Minister Nick Clegg and Transport Secretary Justine Greening, who campaigned against a third runway, are said to be furious at the proposals.
Although building would not take place until after the next election, a strategy review on aviation, along with a paper on 'hub status' is due later this summer.
Secret plans being drawn up at Whitehall include the possibility of transforming the runway at RAF Northolt, a small airport six miles from Heathrow used by the Queen, into an effective third runway, which would not involve the destruction of nearby villages. It could be connected to Heathrow with a 20-minute rail link and would be completed within a few years.
Expanding Gatwick airport would be less controversial, but senior figures say that a global hub would be better positioned in West London.
Both Tory and Lib Dem 2010 manifestos promised there would be no third runway at Heathrow, and the coalition agreement commits both parties to "the cancellation of the third runway at Heathrow" and "the refusal of additional runways at Gatwick and Stanstead."
Click on the image below to find out about new flight routes for summer...