Cabinet ministers opposed to the Government's decision on airport expansion in the south east are to be given temporary freedom to voice their criticisms when the preferred option is announced next week, Downing Street has said.
The highly unusual special arrangement will heighten speculation that the Government is poised to give its backing to a new runway at Heathrow, which has been fiercely opposed by Foreign Secretary Boris Johnson and Education Secretary Justine Greening.
Cabinet discussed the runway issue for over an hour on Tuesday morning, but the final decision in the long-running process of choosing an option for development will be made at a meeting of a Cabinet sub-committee next week, said Number 10.
Theresa May's official spokeswoman declined to say whether the Prime Minister will offer Conservative MPs a free vote on airport expansion when the issue comes to the House of Commons.
The nine members of the airports sub-committee which will make the expansion decision do not include Mr Johnson, whose Uxbridge and South Ruislip seat is located just miles from Heathrow, Putney MP Ms Greening or any other minister representing a London seat.
Mrs May's spokeswoman said this reflected the fact that the choice between the proposed expansion plans for Heathrow and Gatwick recommended as options by the Airports Commission under Sir Howard Davies was a "national infrastructure" decision.
The PM set out the special arrangements for ministers to voice their "personal view" on the eventual decision at this morning's Cabinet meeting, and is due to spell out the details in a letter to colleagues.
She told ministers that a decision on increasing airport capacity in the South East had been "delayed for too long" and that it was important to now take a decision "in the national interest", her spokeswoman told reporters at a regular Westminster media briefing.
Additional capacity would be a boost for UK business and competitiveness regardless of the scheme that the Government chooses, the PM said.
Mrs May's spokeswoman said the decision to give ministers a limited period to voice their personal views was a "mature, common-sense approach reflecting the fact that many ministers have long-held views and that ministers are also MPs and some have specific constituency issues that they have to address".
But she said it was not the expectation that ministers would be permitted to campaign against development following this period.
A "range of views" was expressed in Tuesday morning's discussion at 10 Downing Street, in which a majority of Cabinet ministers took part, said the spokeswoman.
There was a "clear consensus" on the importance of addressing the issue of airport capacity and Mrs May's decision to allow dissenters to speak out was "welcomed around the Cabinet table", she added.
Asked whether Tory MPs would be given a free vote, the spokeswoman pointed out that the Government has not yet set out how it will proceed following the sub-committee decision and whether there will be a vote in the House of Commons.