British Prime Minister Theresa May says she will go the EU to seek changes to the backstop, after British MPs passed an amendment seeking changes to the border 'backstop' guarantee.
The Commons approved two things this evening - to reject the backstop for Northern Ireland, and that they shouldn't leave without a deal.
So Theresa May will now go back to Europe seeking more concessions.
She told the House of Commons: "We will now take this mandate forward and seek to secure legally binding changes to the withdrawal agreement that deal with concerns on the backstop while guaranteeing no return to a hard border between Northern Ireland and Ireland."
She acknowledged "limited appetite" in the EU for such a change, noting that "negotiating it will not be easy".
However. a spokesperson for European Council President Donald Tusk insisted that the withdrawal agreement is "not up for renegotiation".
The statement adds: "If the UK's intentions for the future partnership were to evolve, the EU would be prepared to reconsider its offer and adjust the content and the level of ambition of the political declaration, whilst respecting its established principles."
French President Emmanuel Macron had earlier warned that the existing deal is not up for renegotiation.
Brussels has repeatedly said they will not get rid of the backstop until another option that achieves the same thing - avoiding a hard border - is on the table.
There was no new suggestions tonight.
Theresa May got mixed reaction in the Commons.
Labour leader Jeremy Corbyn agreed to meet her on solutions - which is progress.
However, the SNP accused her of ripping up the Good Friday Agreement with this vote.