By Sarah Young
LONDON (Reuters) - Heathrow, Europe's busiest airport, told a Parliamentary committee on Wednesday that it could still meet environmental standards if it expands.
The airport has been campaigning for years to be allowed to add a third runway because it is operating at full capacity. But it faces opposition from some politicians, local residents and environmental groups.
A government-appointed Airports Commission named Heathrow as the preferred site for a London airport expansion in July. Prime Minister David Cameron has said he will decide by the end of the year whether a new 23 billion-pound ($35 billion) runway should be built there.
Reassurances that the site can meet environmental standards could help provide political cover for the final decision.
The campaign group Stop Heathrow Expansion remains opposed to the plans for Heathrow. It says the airport is the only major UK airport where air pollution levels remains stubbornly above EU legal limits.
According to their website, the campaigners favor expanding at Gatwick, Britain's second-busiest airport. The Commission decided against Gatwick, which has called the Commission's environmental analysis on Heathrow flawed.
Lawmakers on Britain's Environmental Audit Committee heard evidence on a bigger Heathrow's carbon emissions, air quality and noise levels, from Heathrow's chief executive, John Holland-Kaye and Howard Davies, former chairman of the Airports Commission.
The Commission's support for Heathrow was conditional on further restrictions to night flights, introducing a noise levy and a legal commitment on air quality. The conditions were an attempt to win over critics, who battled to get a previous expansion plan scrapped five years ago.
Holland-Kaye told lawmakers that he was confident that an expanded Heathrow would be able to meet EU air quality limits, making a public pledge that the airport would only release capacity from the new runway if it was clear that doing so would not delay compliance with those limits.
"Heathrow today complies with EU air quality limits. We have a very good and robust plan in place to make sure that even with expansion we will continue to do that," he said.
One way of cutting emissions further could be to establish an airport congestion charge for those traveling there by car, suggested Holland-Kaye.
But he wouldn't be drawn on whether the airport would agree to the condition of further night flight restrictions.
"We haven't accepted it yet. It is something that we need to keep working on. We need to discuss with airlines and the government and, I think there is a way through that, and we will make our statement on that in due course," he said.
The airport is stepping up plans to use more electric vehicles within the airport, Holland-Kaye said, and is set to benefit from improved rail connections when London's new east to west rail link, Crossrail, opens in 2018. That should reduce emissions from people traveling there by car.
(Reporting by Sarah Young, editing by Larry King)