Government delays final decision on Heathrow airport expansion

The Cabinet debated the contentious issue yesterday morning, with several members known to harbour concerns about the £9 billion expansion.

A decision on the third runway at the west London airport, which is Britain's biggest, was expected this week.

But a Downing Street spokesman said that, while it was already government policy "in principle" to increase capacity at Heathrow, the final decision was the responsibility of Transport Secretary Geoff Hoon, who would make an announcement by the end of the month.

Opposition to the proposed third runway is gathering strength, with more than 40 backbenchers joining opposition parties and green campaigners in demanding that it be scrapped.

Prime Minister Gordon Brown has agreed to meet with rebels to discuss their concerns. Tory London Mayor Boris Johnson also insisted that he would go to court to halt the third runway.

Mr Johnson, who has called for the construction of a new airport in the Thames estuary instead, said that the "overwhelming majority" of people were against the plan on environmental and economic grounds.

But trade unions Unite and GMB are both campaigning in favour of expanding Heathrow, arguing that it would create 50,000 much-needed construction jobs and up to 15,000 in airport services and that it would safeguard the current 172,000 staff.

Unite joint general secretary Derek Simpson urged: "Now, of all times, we need to seize the opportunities to create more jobs."

Heathrow workers will address MPs today to "set the record straight" about the plans, he said.