Theresa May is to be grilled by a committee of MPs days after the critical December European Council meeting, where the EU27 will decide whether "sufficient progress" has been made on Brexit talks.
The liaison committee, which is composed of the chairs of the other select committees, is the only one with power to call the Prime Minister to give evidence.
Newly-appointed chair Sarah Wollaston announced last night this would be on 20 December. The European Council meets on 14 and 15 December to determine whether "sufficient progress" has been made to unlock the second phase of Brexit negotiations, finally enabling David Davis and his counterpart Michel Barnier to begin discussing trade and transition.
Wollaston, who defected from the Leave campaign to vote Remain, has already rebelled against the government since the summer. The Totnes MP was the only Conservative to defy the whip over a Labour motion on universal credit.
She will be joined by Remain-supporting Tories Nicky Morgan, Tom Tugendhat, Damian Collins and Bob Neill as well as Robert Halfon. Labour MPs on the committee include Yvette Cooper, Rachel Reeves and Frank Field. Liberal Democrat Norman Lamb is also a member.
Last night Wollaston said: "Select committees show Parliament at its best with MPs working together across party lines... I hope to use my time as chair to strengthen the role of select committees and the valuable role the play on behalf of the public.
"Brexit is likely to dominate the government’s agenda in this Parliament but there are very many crucial issues of domestic policy which must not be sidelined."
Yesterday May met with business groups from across Europe to discuss Brexit. During the meeting, which was held at Number 10, the need for urgent clarity was once again put to the Prime Minister and her Brexit secretary David Davis.
But privately, MPs have told City A.M. there is a growing sense within Westminster that the December meeting will end without sufficient progress being declared.
"People here are accepting it won't happen," one backbencher said yesterday.