The Richmond MP, widely seen as the green conscience of the Tory party, told the Financial Times that voters in west London would punish the coalition at the ballot box if ministers reneged on their promise not to allow a third runway.
Goldsmith said that the renewed pressure on the government to change its course was “scaremongering” given that Heathrow already had more flights to business destinations than any other European airport.
“Simply calling on government to double the size of Heathrow is lazy half-thinking by people who ought to know better, but who have been captured by vested interest and are allowing them to do their thinking for them,” he said in a strongly worded riposte.
Mr Goldsmith was the co-author of an environmentally friendly “Quality of Life” report for the Conservative party five years ago, which formed a key plank of the party’s rebranding. He has said he will not stand as a Conservative MP at the next election if the party supports Heathrow’s third runway, a threat which could prompt an awkward by-election for the Tories.
The coalition is deeply split over the issue of aviation, with George Osborne, the chancellor, quietly determined to end the Tory opposition to Heathrow’s expansion if his party wins the 2015 general election. With speculation mounting about the future of Justine Greening, transport secretary, who is opposed to the scheme, Mr Cameron is under pressure to clarify his aviation policy.
Mr Goldsmith said that the Tories and Lib Dems had been “unambiguous” before the election, ruling out any prospect of a U-turn. “To break that promise would be a betrayal too far,” he said.
He argued that the government needed to relieve pressure on Heathrow by improving links to other underused airports such as Stansted and developing a two-hub approach.
“We are well connected, and we have ample capacity. The problem is that we don’t use it well,” he said. “If we want to preserve Heathrow’s hub status, we need to stop clogging it up with point-to-point flights to places like Cyprus and Greece that contribute nothing to overall connectivity.”
That argument was rejected by BAA, Heathrow’s owner and operator, which said the airport’s hub business model was based on passengers transferring off short- and medium-haul flights on to long-distance flights. These arrangements often ensure that long-haul flights are profitable for airlines led by British Airways, the biggest carrier at the airport.
“Moving short-haul flights out of Heathrow would strangle the transfer traffic on which long-haul flights depend,” said BAA. “It would damage the UK’s existing long-haul connections rather than create new ones. Any action which discriminates against certain short-haul flights could also breach EU competition law and risk retaliatory action against UK airlines by other states.”