A cross-party joint statement promoted by the London Borough of Hillingdon was due to be sent to transport secretary Alistair Darling as Planning went to press. It has been signed by more than 60 politicians and groups, including London mayor Ken Livingstone, MPs, MEPs, peers, members of the Greater London Authority and London borough councillors.
Hillingdon council leader Ray Puddifoot said: "Should the white paper not offer a sensible way forward, then we will find someone bigger than them to redress the issue. Heathrow has already been developed beyond the site's capability. If the government thinks it is a viable option, we will join others poised to take court action over this decision."