Heathrow’s third runway would not be enough to cope with passenger demand for flights within the next 30 years, a senior government official has reportedly warned.

Estimates for passenger numbers made three years ago were “already looking quite out of date, with demand at a national level growing 10% faster” than assumed, according to Sarah Bishop, deputy director of aviation policy at the Department for Transport.

By 2050 “we are expecting that there will be capacity constraints once more, even with a third runway at Heathrow,” she told a recent meeting of the Westminster energy, environment and transport forum.

“Capacity in the southeast up to 2030 will be well served with an additional runway at Heathrow, but there may be a need for a runway beyond that looking out to 2050,” Bishop was reported by The Times as saying

Airlines flying in or out of the UK carried 285 million passengers last year, a rise of almost 15 million from a year earlier and up by 30 million in two years.

A fourth runway at Heathrow has been ruled out by government although this would not prevent a future administration from pushing ahead with such a proposal.

However, Gatwick has put forward plans to bring its second emergency runway into full-time use.

Heathrow will hold a public consultation next summer into the £14 billion project to build a two-mile third runway that would increase the annual number of flights from a maximum of 480,000 a year now to 740,000.

Robert Barnstone, co-ordinator of the No 3rd Runway Coalition, told the newspaper: “This beggars belief. One runway isn’t going to meet a multitude of environmental targets, let alone another one.”

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