The opportunity to end "decades of political dithering" on airport expansion has been squandered, says the Transport Committee in its report on airport expansion in the south east.
In a report published today the committee said the decision on whether to expand Heathrow or Gatwick is not the end of the process "but the start of one".
It adds that arguments for and against expansion have changed little in the last 25 years and the government must act now to set a clear timetable for delivery.
Last year, The Airports Commission recommended building a third runway at Heathrow although a final decision has been postponed several times with one not expected now until the summer.
It wanted further work on the impact of pollution and noise before committing to Heathrow, but the committee said this will only lead to more damage to the UK economy.
"The government must make up its mind. The decision on location is not the end of the process, it is the start of one. Real progress cannot begin until the location is declared," said chair of the transport committee, Louise Ellman MP.
"Across the world, cities are collectively planning to build more than 50 new runways with capacity to serve one billion additional passenger journeys by 2036. The growth of large hubs in the Middle and Far East and North America threatens our position as a hub of international aviation. The UK's connectivity with the world's emerging markets is a major concern.
"The months ticking by constitute time wasted for the UK's economic prosperity. UK PLC needs to know that a decision will be taken. Doing nothing means the UK continues to lose out," Ellman said.
A spokesperson for the department for transport defended the government's decision to delay an announcement. “The case for aviation expansion is clear – but it’s vitally important we get the decision right so that it will benefit generations to come.
“As well as progressing the package of further work announced in December, the Government will continue to consider the commission’s evidence before reaching a view on its preferred scheme.
“We are undertaking more work on environmental impacts, including air quality, noise and carbon so we can develop the best package of measures to mitigate the impacts on local people.”
The transport committee said it still supports expansion at Heathrow over Gatwick.