Number 10 has insisted there is no plan B if May’s deal fails, but as Westminster counts down to Tuesday’s meaningful vote on the withdrawal agreement, conversations have taken place between the PM and her closest aides about how she could proceed if it is voted down.

BuzzFeed News understands that several of the PM’s senior allies have raised the prospect of another referendum, with voters offered a choice between her deal and remaining in the EU. Those sympathetic to the idea believe she could win by guaranteeing an end to free movement and have said it is the only way she will be able to secure a mandate for her exit plan.

A source familiar with the conversations said May’s chief of staff Gavin Barwell and chief whip Julian Smith have discussed the merits of a second referendum.

But the source said May has vociferously opposed the idea of another public vote whenever it has been raised, because she believes it is her duty to fulfil the result of the 2016 referendum and cannot risk Brexit being reversed. “It is the only time she loses her temper and raises her voice,” they said. Downing Street declined to comment on private conversations.