LONDON — A British legislator has a question for Prime Minister David Cameron: Are you a man or a mouse?
In the sort of blunt language usually thrown at other parties, a member of Cameron's Conservative Party challenged his leader to be a man and get cracking on expanding Heathrow Airport.
Tuesday's blast from Tim Yeo, a long-serving member of Parliament and chairman of the Energy and Climate Change Committee, was the rudest shot yet in a campaign by airlines, business groups and unions demanding that Cameron ditch his opposition to a third runway at Heathrow, Europe's busiest airport, serving 70 million passengers a year.
"The prime minister must ask himself whether he is man or mouse," Yeo wrote in The Daily Telegraph, a Conservative-supporting newspaper that splashed the question in a front-page headline.
Opposition to the third runway was Cameron's initiative four years ago as he worked to make his party appear more sensitive to environmental issues. Justine Greening, Cameron's transport secretary, supports her constituents in west London in opposing another runway.
Greening's department is launching a consultation to set long-term goals for preserving London's status as an aviation hub. Conclusions would be published in March, and only then would the department look at specific moves to increase capacity.
The recent pressure on Cameron is partly in anticipation of a shuffle of Cabinet positions. Dismissing Greening, say some Conservatives, would be a strong early signal that the third runway project is back on.
"Does he want to be another Harold Macmillan (prime minister 1957-1963), presiding over a dignified slide towards insignificance? Or is there somewhere in his heart ... a trace of (Margaret) Thatcher, determined to reverse the direction of our ship?" Yeo wrote in his op-ed piece.
Cameron's office said the prime minister would keep his promise to oppose a third runway during the life of the coalition government, which is due to end in 2015.
"We don't see the argument for a third runway," a spokeswoman for Cameron said, speaking on condition of anonymity.
The Institute of Directors, representing 38,000 directors of U.K. businesses, weighed in to support Yeo.
"There is no doubt that we need more airport capacity, and the longer the government delays deciding where it will be, the more chances for trade we will miss," said Simon Walker, the Institute's director general.
British Airways, the biggest tenant at Heathrow, has been equally forceful in pressing Cameron to change direction.
"I don't believe this government has the political will to address the issues," Willie Walsh, chief executive of International Airlines Group, BA's owner, said last month.
"David Cameron seems a lot happier clapping and cheering for (Olympic) gold medals than dealing with tough, long-term economic challenges," Walsh said in the interview with the Financial Times.
London Mayor Boris Johnson, a potential rival to Cameron, wants to build an entirely new airport — dubbed "Boris Island" — east of London near the mouth of the River Thames. "Heathrow is fundamentally not the place" for expansion, he has said.
Heathrow, the hub of long-haul flights, is operating at capacity, with 1,300 landings and takeoffs every day.
Whatever happens, airlines could not expect any additional capacity at Heathrow or any other London airport before 2020.
For Cameron, it's a tough and immediate issue.
Gordon Brown's Labour government approved a third runway for Heathrow in 2009, in the face of loud opposition from people living around the airport.
Cameron canceled the project when he formed a government following the 2010 election, and no third runway is part of his coalition agreement with the Liberal Democrats. Labour's new leader, Ed Miliband, has reversed his party's support for a third runway as well.
Business groups back the third runway as job-creating economic boost for the flat-lining British economy. There are worries that Heathrow is losing ground against continental competitors such as Frankfurt airport and Paris' Charles de Gaulle airport.
Conservative legislators such as Yeo are also likely to worry about their party's poll standing, roughly 10 points behind Labour through the summer.
A study published by the British Chambers of Commerce earlier this year claimed that a third runway would add 30 billion pounds ($48 billion) a year to the U.K. economy, and that every year of delay cost the nation about 1 billion pounds.