Four councils have delivered a damning verdict on the UK Airports Commission’s decision to recommend expand Heathrow, arguing legal and environmental barriers were ‘either misunderstood or deliberately underplayed’.

Hillingdon, Windsor and Maidenhead, Richmond and Wandsworth councils claim their assessment exposes ‘a series of flaws and persistent bias’.

They have now handed a report to MPs ahead of a possible vote in the Commons on Heathrow’s expansion.

The commission’s own forecasts show a new runway at Heathrow will lead to just five extra long haul routes by 2050 and that regional airports will suffer loss of business as a result, according to the councils’ report.

It also said the Commission had confirmed nitrogen dioxide levels around Heathrow were illegal and would get worse with an additional runway.

Ray Puddifoot, leader of Hillingdon Council, said: ‘The critical factors which present the biggest challenge to a potential third runway have been either avoided, or worse, misinterpreted by the commission.

‘There is a distinct lack of information on air quality and flight paths and instead there are inflated claims about a colossal economic windfall that the commission says will come from a handful of new trade routes. It’s clear to me that the case for expansion at Heathrow doesn’t add up and a third runway will never happen, no ifs or buts.’

Ravi Govindia, leader of Wandsworth Council said: ‘The Airports Commission’s recommendation points the way to more wasted years and another failed runway scheme. Heathrow is simply in the wrong place and there is no realistic prospect of overcoming the complex physical, legal and environmental factors that will always constrain its growth.’

Windsor and Maidenhead Council leader, David Burbage, said: ‘We are asking MPs to consider carefully whether a scheme that is forecast to deliver a net reduction in direct routes between Heathrow and domestic airports is really in the interest of regional economies and local people.

'The third runway is the wrong choice for London and the south east and would greatly reduce regional connectivity and economic competitiveness. For the millions of people who are neighbours to the airport, this would be very damaging.’