MPs voted in favour of the government's Brexit deal but then rejected the PM's plan to fast-track a bill through Parliament to implement it.
Opposition to the deal is still strong in some quarters.
Northern Ireland’s DUP withdrew its support for because it would lead to a customs border in the Irish Sea. The Scottish and Welsh governments believe it could undermine the powers of their devolved legislatures.
So what could this deal mean for the future of the United Kingdom? And what might it mean for the future relationship between the UK and the EU? And could Brexit still be derailed by groups which are implacably opposed to it?
David Aaronovitch is joined by:
Jill Rutter - Senior Research Fellow, UK in a Changing Europe Rob Ford - Professor of Politics, University of Manchester Sam Lowe - Senior research fellow, Centre for European Reform Alison Young - Professor of Public Law, University of Cambridge Sam McBride - Political editor at The Belfast News Letter
Producer: Serena Tarling Editor: Jasper Corbett