http://www.bbc.co.uk/news/uk-34971277
The government should not support the building of a third runway at Heathrow until a number of environmental conditions can be met, MPs have said.
The Airports Commission published a report backing a third runway in July.
But the House of Commons Environmental Audit Committee report said firm plans to deal with climate-changing emissions, air quality and noise need to be put in place.
A final government decision is expected by the end of the year.
Labour MP Huw Irranca-Davies, chairman of the committee, said it would be “irresponsible” to postpone dealing with the environmental impact of expansion at Heathrow.
He warned that to do so “could lead to legal challenges as a result of the potential damage to public health from increased air pollution and noise”.
“If the government decides to accept the commission’s recommendation for a third runway in principle, we will seek assurances from the secretary of state for transport that environmental conditions will be met before it is given final approval,” he added.
BBC business editor Kamal Ahmed said senior sources at the company that runs Heathrow have told him the “mood music” around the decision to expand is in favour of the third runway being approved.
The cross-party committee said legal air pollution limits would have to be reached if the west London airport expands and also called for a ban on night flights to ease noise.
The MPs said the airport had to show that an expanded Heathrow would be less noisy than it is with two runways. Their report also called for Heathrow to say it would cover the costs of surface transport improvements.
The Airports Commission has already called for flights between 23:30 and 06:00 to be banned.
Heathrow currently has said it wants a “review” of the issue and has not made any pledges over night flights. The airport has also said it plans to ensure more people arrive by public transport to keep emissions down.
‘Policy vacuum’
Mr Irranca-Davies said: “The communities living near to the roads around Heathrow already put up with noise and extra traffic.
“It would be quite unacceptable to subject them to a potentially significant deterioration in air quality as well.”
A strategy to deliver aviation emissions at no higher than 2005 levels by 2050 should be put in place by the government, the committee’s report recommended.
It also called for a Community Engagement Board to be set up to increase trust between local residents and the government.
Mr Irranca-Davies said: “Planes are becoming more fuel efficient, but this alone will not keep aviation emissions in line with the government’s climate change targets given the growth in passenger numbers.
“Even without expansion, aviation is on track to exceed its climate change target. We heard evidence that those targets might be met in theory, but at present there is a policy vacuum and evidence-based scepticism as to whether they can be met in practice.”
Heathrow’s chief executive John Holland-Kaye told the committee earlier this month that the airport could comfortably expand to include a third runway and still stay within environmental targets.
At the time, he said the issue of night flights was one that Heathrow was looking at and would comment on “in due course”.
The issue of Heathrow’s expansion has been a long-running and contentious issue.
In 2009, while in opposition, David Cameron ruled out Heathrow expansion, saying “no ifs, no buts”.
The Airport Commission’s recommendation in July was criticised by competing airport Gatwick, and by London Mayor Boris Johnson, who has argued for a whole new airport.
Environmentalists and residents who live near the flight path of the proposed third runway have also campaigned against it.