A campaign group of more than 20 councils affected by Heathrow believe the airport's proposals for a third runway will inevitably be followed by demands for a fourth.

The airport yesterday revealed plans for three potential locations for its next landing strip - each of which would create new flightpaths over the most densely populated part of the UK.

But the all-party 2M Group is also challenging the airport's claims that it can reduce noise suffering while increasing the number of flights over London.

The councils say that noise nuisance data used by the airport is 30 years out-of-date and understates the number of people who suffer under the existing and proposed flightpaths.

Ravi Govindia, Leader of Wandsworth Council and spokesman for the 2M Group, said: "Heathrow might be offering a choice over where their next runway goes but we they won’t stop until they have four.

"Some parts of London and the Home Counties may escape the new flightpaths this time round but the peace won’t last for long.

"To claim they can reduce noise while increasing the number flights over London is a complete sham and won’t stand up to scientific scrutiny.

"They grossly understate the number of people who suffer under their existing flightpaths and continue that trend with these projections.

"We calculate that around three million people will be affected by aircraft noise if the airport expands to four runways.

"They offer nothing new to solve the surface access and air pollution issues which scuppered their previous third runway plan in the High Court. This is a fight they can’t win."

Heathrow revealed its latest expansion plans in a submission to the Government's aviation commission.

2M has consistently argued that Heathrow will not stop expanding if granted a third landing strip.

Its main European rivals have four or more runways and Heathrow will seek to match their capacity.

Charles de Gaulle, Heathrow's nearest rival, has four runways while Frankfurt and Barajas (Madrid) also have four and Schiphol (Amsterdam) has six.

The 2M Group is an all-party alliance of local authorities concerned about the environmental impact of Heathrow operations on their communities.

Members are not anti-Heathrow but work together to improve the environment and protect the quality of life for local people.

The group, which took its name from the 2 million residents of the original 12 authorities, now represents a combined population of 5 million people.

The previous government approved Heathrow’s plans for a third runway in 2009.

In 2010 the 2M Group challenged that decision in the High Court on environmental grounds and successfully overturned the government’s ruling.

Lord Justice Carnwath's ruled a third runway 'untenable' because:

• The area around Heathrow already exceeds EU pollution limits due to aviation emissions and congestion on surrounding roads.

• The additional rail infrastructure required to support additional runway capacity has not been identified. 

• A credible, contemporary measure for the onset of community annoyance from noise has not been established 2M asserts that a robust assessment of Heathrow's noise, transport and air quality impacts will rule out new runways, rule out more intensive use of existing runways and highlight the need to phase out early morning flights.