The Democratic Unionist Party say they won't back Boris Johnson's Brexit deal, suggesting it would not be "in Northern Ireland's long-term economic and constitutional interests."
The Prime Minister announced this morning that there was 'white smoke' from Brussels and a deal had been agreed with EU chiefs.
But Johnson still needs to get MPs to sign off on the deal when he returns on Saturday - and he is dozens of votes short of a majority in the house.
The 10 DUP MPs were crucial to this arithmetic - not only because of their votes, but because many Brexiteer Tory MPs take their cues from the hardline Northern Irish party.
In a statement, the DUP said: "Following confirmation from the Prime Minister that he believes he has secured a "great new deal" with the European Union the Democratic Unionist Party will be unable to support these proposals in Parliament.
"The Democratic Unionist Party has worked since the referendum result to secure a negotiated deal as we leave the European Union. We have been consistent that we will only ever consider supporting arrangements that are in Northern Ireland's long-term economic and constitutional interests and protect the integrity of the Union."
After subtracting the MPs who don’t vote - chiefly Sinn Fein and the deputy speakers - Johnson needs to convince 320 MPs to vote for his deal.
If every Conservative MP who is able to vote also backs the deal, this gives the Government 285 votes.
The most Theresa May ever managed was 279 - and she hadn’t just effectively sacked 19 of her MPs for disloyalty.
