Conservative cabinet ministers will be allowed to rail against their own government’s decision on airport expansion - in the clearest hint yet that Heathrow will be given the nod.

Ministers will finally make a decision on where to build an extra runway next week.

Long-term opponents of a third runway at Heathrow, including the Foreign Secretary Boris Johnson and the Education Secretary Justine Greening, have been told that they will be able to criticise the decision “temporarily”.

But they could still be forced to back it in a vote in the House of Commons, No 10 suggested.

The choice, between Heathrow and Gatwick, is due to be made next week by the cabinet sub-committee on airports, whose members include the Scottish Secretary David Mundell.

No London MPs sit on the 9-strong committee, which also includes Mrs May, the Chancellor Philip Hammond, Business Secretary Greg Clark, Transport Secretary Chris Grayling, Communities Secretary Sajid Javid, Environment Secretary Andrea Leadsom, Chief Whip Gavin Williamson and Conservative party chairman Patrick McLoughlin.

The decision to suspend collective responsibility, even temporarily, could save Ms Greening and Mr Johnson from being forced to resign.

Both have campaigned vigorously against the expansion of Heathrow.

Ms Greening has warned that a third runway would adversely affect her her constituents in Putney, south west London.

Mr Johnson vociferously opposed the idea of a third runway at Heathrow when he was mayor of London.

He even proposed an alternative, a new airport by the Thames in east London, nicknamed ‘Boris Island’.

Last week the Scottish Government backed plans for Heathrow expansion, saying the move could create up to 16,000 jobs across Scotland.