The government is being urged to review Heathrow’s third runways plans as it has done for the HS2 high-speed rail link.

The call to transport secretary Grant Shapps came from the backers of alternative Heathrow runway extension scheme Heathrow Hub.

The scheme’e legal advisor wants a review of the government decision to support the building of a third runway at the London airport.

Heathrow Hub claims two “significant changes” have emerged since the government backed the third runway, which means that the policy statement is now out of date.

It cited “mounting evidence” that the proposal’s costs are rising from the original five year old estimate of £14 billion.

Also, the UK net zero carbon emissions target by 2050 means “it is hard to see how airport expansion on this scale is compatible”.

A Heathrow Hub spokesman said: “As time goes on it becomes clearer that the government has made a big mistake in backing the third runway.

“Its ballooning costs will ultimately be borne by consumers via higher passenger fees; and the resulting carbon emissions do not seem remotely compatible with the net zero by 2050 target.

“Instead of fighting for the third runway in court, Boris Johnson and Grant Shapps should announce an urgent review, just as they have of HS2.”

Heathrow Hub claims its plan would be “cheaper, quicker to build, greener and less disruptive”.