Birmingham International Airport last night shrugged off a Conservative Party threat to hit the aviation industry with a moratorium on expansion, insisting a planned runway extension would do more good than harm.

Proposals by the Conservative Quality of Life Policy Group propose scrapping new runways at Stansted and Gatwick and testing all other airport expansion against the "challenge of climate change".

The policy group, chaired by the environmentalist Zac Goldsmith, also wants to charge VAT on tickets for UK domestic flights and impose Air Passenger Duty on a per-flight basis rather than per passenger and increase it on a year-by-year basis.

John Morris, director of communications at BIA, said the Conservative proposals should not threaten the planned £120 million extension of the airport's main runway, which would allow planes to fly non-stop to China and the west coast of America.

Mr Morris said the longer runway would be environmentally friendly because it would allow millions more passengers to fly from their local airport in Birmingham rather than driving to Manchester, Heathrow or Gatwick.

He added: "More than eight million people live within an hour's drive of BIA, but only 40 per cent actually use the airport because the short runway does not allow non-stop long haul flights. That means many more car journeys and congested motorways.

"When we extend the runway we will be able to take a lot of journeys off the roads because we will be clawing back the market. It is about getting the right balance as far as we are concerned.

"We are conscious that all political parties are putting the environment on the agenda and we have to take that into account in our plans for future expansion."