Heathrow Airport could get a third runway and a sixth terminal to help it cope with a surge in air travel, the government said on Thursday, despite fierce opposition from environmental campaigners.
Transport Secretary Ruth Kelly said Europe's biggest airport must expand to handle hundreds of thousands of extra flights that are expected in the next 25 years.
Her supporters, including business groups and unions, say it will create jobs, pump billions into the economy and make Heathrow more competitive.
Critics, however, say the expansion will contribute to global warming, increase pollution and blight the lives of millions of people under the flightpaths.
The developments are being closely watched by governments and campaigners across Europe, including Frankfurt, Paris and Stuttgart, where airport expansions are planned.
"If nothing changes, Heathrow's status as a world-class airport will be gradually eroded -- jobs will be lost and the economy will suffer," Kelly said in a statement.
The government backs an expansion in air travel, which is set to double in the next 25 years.
The proposals include building a third runway for short-haul flights and new terminal to handle 702,000 air traffic movements by 2030, compared to the current limit of 480,000.
British Airways Chief Executive Willie Walsh said benefits could be worth more than 9 billion pounds each year.
Airport operator BAA, part of Spain's Ferrovial said it would bring economic benefits through tourism, job creation and businesses relocating to be near Heathrow.
"It is a very considerable economic powerhouse," BAA Chief Executive Stephen Nelson told BBC radio.
Critics question the economic benefits. They want the expansion plans dropped and the growth of air travel halted.
John Stewart, chairman of anti-airport expansion group HACAN ClearSkies, told the BBC: "There's a mantra here that it's important for the economy. What has never been worked out is how those figures are arrived at."
Liberal Democrat transport spokeswoman Susan Kramer said it "makes a mockery of any attempts to tackle climate change".
"It is time for ministers to listen to the public and stop any further Heathrow expansion," she said.
Scientists say air transport contributes to global warming, and the carbon dioxide gas and water vapour emitted by aircraft are four times more potent at high altitude than at sea level. ( Reuters )