Gatwick says it will build another runway, even if Heathrow is chosen as the preferred site when the Government finally makes it mind up about airport expansion.
The West Sussex airport believes expansion at Heathrow will be not be straightforward, even if it wins the right to expansion, because of concerns over the environment and other issues.
A spokesman for Gatwick said: "Gatwick would be standing ready to deliver the new (second) runway as, should Heathrow get the green light, it is likely to fail as it has several times before," according to the Press Association.
The spokesman added that, even if MPs vote in favour of Heathrow, the project would never get off the ground because of environmental obstacles, legal challenges and concerns over the cost of upgrading transport links.
"A decision on next steps will be taken after the Government announcement on new runway capacity. While Gatwick does not rule out launching legal action, other groups have already said they would if Heathrow expansion is green-lighted."
Gatwick said: "We are not going to stop making our case to government, whatever they decide."
