Council chiefs are describing court action over Heathrow a 'real possibilty' as they vow to continue their fight against expansion of the world's busiest international airport.

Legal advisers are considering whether to challenge last Thursday's Government ruling on the growth of Heathrow, either on the grounds the airport is already breaching several environmental guidelines or 'flaws' in the consultation process.

An announcement by Geoff Hoon in the House of Commons approved the building of a third runway and a sixth terminal at the transport hub.

London Mayor Boris Johnson is willing to support a legal challenge, which is now being discussed by West London councils and could include Hammersmith & Fulham.

Mr Johnson said: "I am deeply concerned that the proper process of coming to this decision may not have been followed and I will support a legal challenge should this prove to be the case. To this end we are currently considering the announcement in detail."

Kensington and Chelsea Council added its voice to a growing chorus condemning the Government's decision to approve a third runway.

Deputy Leader Cllr Daniel Moylan said: "We will continue to lobby the Government and expose their flawed case for unchecked expansion."

The true strength of opposition to a third runway for the airport emerged last week after transport chiefs revealed details of the responses to its consultation document. Out of nearly 70,000 comments received by the Department for Transport (DfT), only just over 8,000 (11 per cent) supported any form of expansion. More than half the respondents raised concerns about pollution and nearly as many said noise was an issue.


WHAT GEOFF HOON'S ANNOUNCEMENT MEANS FOR WEST LONDON

BUILDING A THIRD RUNWAY AND SIXTH TERMINAL (APPROVED): Last week's decision means work could start on a third runway as soon as 2015 and the landing strip is likely to be open by 2020. Capacity will increase from 480,000 flights a year to 605,000 by 2020, providing EU pollution limits (currently being breached around Heathrow) can be met. The number of flights could increase further to 702,000 by 2030 if the Civil Aviation Authority is satisfied noise and air quality limits will not be broken. Gordon Brown has promised a Parliamentary debate on expansion, although there will be no vote. The airport's owner BAA must now begin the lengthy planning process, which will almost certainly not be completed before the next general election, likely to be held next spring. Should the Tories win, they have promised to scrap the third runway, though legal experts have warned this may lead to a hefty compensation claim from the aviation industry.

MIXED MODE (REJECTED): Runway alternation guarantees eight hours of peace a day for residents living under the flight path. One runway is used for landings and the other for take-offs between 7am and 3pm, and the pattern is reversed from then until the day's final flight. Ending this would have reduced delays and provided additional capacity at the airport, but Geoff Hoon said consultation showed the restriction was valued too highly by Heathrow's neighbours