Ministers have been urged to set out a clear timetable for airport expansion in the South East.
The Commons' Transport Select Committee claimed the arguments for and against increasing aviation capacity "have changed little in a quarter of a century".
It issued a report which stated that the opportunity to end "years of political dithering" by accepting the recommendation of the Airports Commission to build a third runway at Heathrow had been "largely squandered".
But the Department for Transport (DfT) insisted "it's vitally important we get the decision right".
In December the DfT confirmed that the commission's shortlisted options - new runways at Heathrow or Gatwick, or extension of an existing runway at Heathrow - were "viable".
But it also announced that further work on noise, pollution and compensation - which it expects to be concluded "over the summer" - will be carried out before it makes a decision on which project to support.
The select committee claimed the Government had simply confirmed "what was already known" and the case for carrying out further work had not been made publicly.
Labour MP Louise Ellman, chairwoman of the committee, said: "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. Work on environmental issues can run in parallel with other pre-construction work."
She said that more than 50 new runways are being planned around the world and the growth of large airports in the Middle East, Far East and North America threaten the UK's standing in the aviation sector.
Ms Ellman added: "The months ticking by constitute time wasted for the UK's economic prosperity."
Dr Adam Marshall, acting director general of the British Chambers of Commerce, said: "Business doesn't want a timetable. It wants a decision and it wants it fast."
Prime Minister David Cameron was accused of sacrificing the UK's economy for political advantage when the delay was announced last year.
Critics claimed it was a politically-inspired move to avoid damaging resignations by high-profile Tories - including London mayoral candidate Zac Goldsmith, who has vowed to quit as an MP if Heathrow is approved.
The contest to succeed current City Hall incumbent Boris Johnson - himself implacably opposed to the £18.6 billion third runway project - takes place on Thursday.
A spokesman for Heathrow said: "The real, independent evidence continues to point towards Heathrow."
But Gatwick issued a statement which claimed "decades of delay and false starts" on airport expansion couldn be ended only by giving Gatwick the green light.
A DfT spokesman said: "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 possible package of measures to mitigate the impacts on local people. We anticipate that this work will conclude by the summer."