The party conference in Brighton yesterday passed a motion pushing for better use of existing capacity rather than building a new airport in the Thames estuary or new runways at Heathrow, Gatwick or Stansted.
However, the motion that was passed did support an independent study to find a location for a hub airport or a suitable airport to expand into a hub for the long-term.
Liberal Democrat transport minister Norman Baker said: “With this motion, the Lib Dems have sent a very clear message - we are pro economic growth, but we cannot, and will not walk away from our commitments to the environment.
“We said in our manifesto that we are against the third runway. We said it again in the coalition agreement, and I said it again to conference today. There will be no third runway on our watch.”