As the deadline approached for submissions to the Davies Commission on aviation capacity, Ryanair waded into the debate by demanding new runways at all three of the capital's three main airports.
The Irish airline claimed that an additional runway at each of Heathrow, Gatwick and Stansted would provide enough capacity for the next half-century.
Ryanair's chief executive, Michael O'Leary, described Sir Howard Davies Airports Commission as "Another example of David Cameron kicking the can down the road". But he added that it "offers a unique opportunity to finally introduce effective competition and excess capacity in London's runway infrastructure".
Mr O'Leary said: "Three new runways at the three competing London airports is the only sensible and consumer-focused solution to the chronic runway capacity shortages in London and the South East. We cannot wait 30 years and allow billions of pounds to be wasted on 'Boris island'."
The owners of Ryanair's main base, Stansted, were lukewarm about adding another runway. The short-term aim at the Essex airport is to try to win back the passengers who have deserted it over the past six years.
Manchester Airports Group, which bought Stansted earlier this year for £1.5bn, told the Davies Commission that the airport could handle twice as many planes and passengers as it does now without significant investment in new infrastructure.
The previous owners, BAA, hoped to build a second runway with a price tag of £4bn, but abandoned the plan in 2010 in the face of opposition and declining passenger numbers. Usage has fallen by 27 per cent from a peak of 24 million passengers in 2007 to 17.5 million last year.
Manchester Airports Group's chief executive, Charlie Cornish, said: "Developing new capacity at a number of airports is likely to be best for passengers". However, he left the door open for the advisory body to recommend additional capacity saying: "Whichever path the Commission takes, the costs and the environmental impacts of building new capacity at Stansted are likely to be far lower than at alternative locations".
The cost of constructing a four-runway airport at Stansted, able to handle up to 160 million passengers a year, is estimated at £10bn. This week Heathrow's owners said that a third runway would cost a minimum of £14bn.
The Essex airport claims that, even with new runway capacity, the noise impact would be minimal compared with Heathrow: "Stansted handles 50 times as many passengers as Heathrow for every person affected by noise".