Heathrow's owners could be sued for millions of pounds in compensation by Hounslow health chiefs amid claims a third runway would seriously damage the well-being of residents living nearby.

Board members at NHS Hounslow (formerly Hounslow PCT) have discussed how they would seek the massive payout should BAA get the go-ahead to increase flights by up to 50 per cent.

The trust says airport noise and pollution can cause asthma and mental health problems as well as lowering life expectancy for those with existing heart and respiratory problems.

In the minutes of a board meeting held earlier this year, members discussed how they would work with Hounslow Council and the NHS to push for compensation from BAA Heathrow for the increased workload.

"There would be increased financial pressures on the PCT and added strain on health services from the direct effects of the development and from the increased numbers of airport passengers using the local NHS," said the trust's former chief executive John James. "Should the development proceed we would expect it to be on condition that the impact on local health and well-being was monitored so additional remedial action could take place if needed, and the costs from doing so were met by the airport operators."

NHS Hounslow, which began the year £22 million in the red and has been given three years to pay off its historic debt, added that BAA could face similar claims from eight other trusts lying under the flight path.

A BAA spokesman said: "If the Government takes a policy decision to support future growth at Heathrow, a full health impact assessment would be conducted as part of any planning application.

"A third runway will not go ahead unless air quality is better than today and there are improvements to public transport.

"This is not growth at any cost, this is growth within strict environmental limits."