Boris Johnson has told the EU the backstop is a 'bridge to nowhere' as he outlined his plans to replace it.
The British Prime Minister has sent his plans to the European Commission saying it would be a failure of statecraft if they can't reach a deal.
This is Boris Johnson's 11th hour compromise and does contain something of a shift in policy.
He's proposed Northern Ireland keeps all of the EU rules on goods, food and livestock to avoid the need for checks at the border.
This would be contingent on the Stormont Executive approving that, and having a vote on whether to stay aligned with the EU or switch to UK rules every four years.
Johnson has also asked for a UK wide customs territory to allow them to do free trade deals elsewhere.
He said the single market could be protected while doing this - managing it with technology and electronic paper trails, as well as checks at factories and other points away from the border.
The Prime Minister also spoke of a new deal for Northern Ireland - hinting at a large investment package to come.
That may be what has got the DUP on side with the plan.
But the reaction in Dublin and Brussels is as important.
Earlier the Taoiseach said he didn't think it was the basis for a deal, though he hadn't seen the full text at that time.
The EU will have to judge whether it's concrete enough to protect the single market and avoid border checks.
But it may be a starting position for more serious negotiations, just two weeks out from the key EU summit