Earlier this year an independent commission backed the building of a third runway at Heathrow subject to “legally binding” limits on noise levels but opponents say the restrictions would be insufficient to limit the impact on those living under the flightpath.
Ministers were expected to make a final decision by the end of this year but this has now been put off until next Summer.
The Department for Transport says the government “has accepted the case for airport expansion in the south-east” but “will undertake a package of further work” before deciding whether to approve expansion at Heathrow or Gatwick.
This work will include reviewing the Airports Commission’s air quality analysis and drawing up a “package of measures to mitigate the impacts on local people and the environment.”
Transport Secretary Patrick McLoughlin said: “The case for aviation expansion is clear – but it’s vitally important we get the decision right so that it will benefit generations to come. We will undertake more work on environmental impacts, including air quality, noise and carbon.
“We must develop the best possible package of measures to mitigate the impacts on local people. We will continue work on all the shortlisted locations, so that the timetable for more capacity set out by Sir Howard is met.”
Mayor Boris Johnson said the decision meant Heathrow’s efforts to win approval for expansion had been “officially grounded”.
He added: “They have put a superhuman effort into bouncing the Government into a quick decision in their favour but the Prime Minister and his colleagues have refused to allow themselves to be hustled.
“The wheels are falling off the Heathrow fuselage and I think that, now the Government has hit the pause button, they will begin to understand with ever greater clarity that, due to the environmental impacts, the legal obstacles and the cost to the public purse, this bird will never fly.”
Mr Johnson also repeated calls for ministers to back his plans for a hub airport in the Thames Estuary, an option which failed to be shortlisted by the commission.
Sadiq Khan, Labour’s candidate to succeed Mr Johnson next May, claimed the government had delayed making a final decision “to avoid embarrassing” rival Zac Goldsmith who has pledged to resign his Richmond Park seat if Heathrow was allowed to expand.
As a Minister in the last Labour government Mr Khan backed a new runway at Heathrow but says a recent Supreme Court ruling on the need to tackle poor air quality has changed his mind.
Although now opposed to Heathrow he supports allowing Gatwick to increase its capacity.
Speaking after the government’s announcement, he said: “We can’t afford more dithering over aviation capacity. Businesses desperately need more airport capacity around London, and the Tories are letting them down.
“Gatwick stands ready to deliver it sooner, at a lower public expense and without the damaging impact of Heathrow expansion.
“We already know Heathrow can’t be the solution. The additional damage from air and noise pollution would mean more years of delay, while protracted legal battles are fought. It must be Gatwick – and we need to get on with it.”
Mr Goldsmith said he was “absolutely delighted” that ministers have agreed to “judge the options against an environmental test.”
He added: “We know that any airport expansion must meet our legally binding carbon, noise and air quality limits. There can be no doubt that in a fair contest on air quality, Heathrow will not win.
“The choice has always been between an outdated model which would lead to higher costs and less choice, or investing in a network of well connected and competing airports.
“If elected mayor I will continue to make the case for the latter and bring the same focus and discipline to getting things done for Londoners.”
Audio: Mayoral candidates vow to oppose third runway at Heathrow
John Holland-Kaye, Chief Executive of Heathrow Airport, insisted his company “can meet tough environmental standards”
He added: “We have support locally and nationally from politicians, business, trade unions and the aviation industry for Heathrow expansion. Let’s get on and build a better future for Britain.”
Business leaders have criticised the delay in making a final decision.
Carolyn Fairbairn, Director-General of the CBI, called the government’s announcement “deeply disappointing” and warned a failure to increase air capacity would cost the UK £5.3 billion a year in lost trade by 2030.
John Dickie from business lobby group London First said: “The government’s choice to kick the airports decision into the long grass is a failure of political leadership.”
Speaking ahead of the DfT’s announcement Colin Stanbridge, London Chamber of Commerce and Industry Chief Executive, said: “I fear that the government’s current approach on airports is an unnecessary ‘mess’ that perhaps owes more to political calculations related to next year’s mayoral contest.
“However, those calculations could unintentionally ground the UK economy by eroding confidence and generating confusion among potential infrastructure investors.”
