A leaked Whitehall document suggests Theresa May could hold a free vote on expanding airport capacity, potentially allowing some cabinet ministers to oppose a third runway at Heathrow.
The Cabinet Office paper, photographed on the tube and passed to Channel 4 News, examines the possibility of waiving collective responsibility for any vote on the highly controversial issue of expanding an airport in south-east England.
It does not specifically mention Heathrow but there are several cabinet ministers whose constituencies could be affected by a third runway including Justine Greening, the education secretary, Philip Hammond, the chancellor, and even May herself.
The document discusses “potential waiving of collective responsibility” ahead of “the forthcoming decision around airport capacity”.
It also looks at the possibility of “allowing ministers to speak against the government’s position in the House” as they did in the EU referendum campaign.
It is the second time papers have revealed secret information in a week after an official was photographed with a document discussing plans to bring in new grammar schools.
A government spokesman said: “The government remains committed to taking a decision on airport expansion and delivering additional runway capacity as planned by 2030. We will set out next steps in due course.”
The decision was repeatedly delayed under David Cameron, who once ruled out a third runway at Heathrow with “no ifs, no buts”.
That option was recommended by the Davies commission in 2015 but put off for further environmental studies until after the London mayoral election in which Tory candidate Zac Goldsmith was fiercely opposed to expansion.
May is personally chairing a cabinet committee to make the final decision on Heathrow’s third runway plan in order to push for a resolution by October. The prime minister’s Maidenhead constituency is under the night flight route and she was not a member of the influential committee as home secretary under Cameron.
In July, it was reported that a deleted web archive from the late 2000s revealed May had been a strong critic of airport expansion in west London, saying her constituents faced the “prospect of a reduction in their quality of life with more planes flying overhead”.
Cameron took personal charge of the committee and was accused of “locking out” anti-Heathrow cabinet members such as Greening, who was then international development secretary.
The MP for Putney, Roehampton and Southfields is one of the most vocal critics of Heathrow expansion. “Trying to expand Heathrow is like trying to build an eight-bedroom mansion on the site of a terraced house,” she told the Telegraph. “It is a hub airport that is just simply in the wrong place.”
Boris Johnson, the foreign secretary, opposed the third runway as London mayor and Hammond said last year that he was in favour of expanding Gatwick instead. “London’s role as an international air transport hub can be maintained without additional runways at Heathrow,” he said.
“A second runway at Gatwick, plus enhanced transport links between the airports and better transport links to London will create a ‘virtual’ hub airport, maintaining Heathrow’s role in the local economy without expanding it.”
The inquiry into airport expansion in the south-east concluded last year that a third runway at Heathrow was the best of three shortlisted options, rather than extending an existing Heathrow runway or building a new one at Gatwick. In December, the government postponed a final decision pending new analysis of the environmental impacts.
In July, 36 Conservative MPs, led by the former party chairman Grant Shapps, wrote to May to demand a decision on Heathrow, saying it was “a matter of extreme urgency”.
