Plans to expand London's other airports are already further along than Heathrow's and have in the past been viewed as an alternative to a third Heathrow runway. Work is set to start this year to expand capacity at Stansted's terminal. The government is due to make a decision on Gatwick airport by 27 February.

Britain's Labour government will back the construction of a third runway at London's Heathrow Airport to boost trade and economic growth, finance minister Rachel Reeves said on Wednesday. Successive governments have dithered over whether to expand the site to the west of London,

The third runway is part of its drive to lift the U.K. economy out of a long period of stagnation, Treasury chief Rachel Reeves said in a speech on Wednesday.