All 27 remaining European Union leaders signed off Britain's Brexit deal at a special summit on Sunday -- but the real test is yet to come.
Less than an hour after members gathered in Brussels, European Council president Donald Tusk tweeted that they had endorsed the "Withdrawal Agreement and Political Declaration on the future EU-UK relations."
The agreement is a small victory for British Prime Minister Theresa May, who must now persuade UK Parliament to vote for the deal.
German Chancellor Angela Merkel and European Commission President Jean-Claude Juncker greet each other in Brussels on Sunday.
Given that opposition parties -- not to mention many lawmakers within May's Conservative party and the Northern Irish DUP, which supports her minority government -- have indicated they'll vote against it, the deal is far from sealed.
Shortly after European leaders endorsed the deal, DUP leader Arlene Foster reiterated that her party "will not be able to support" it, during an interview on the BBC's Andrew Marr Show.
If UK lawmakers do approve the deal, which looks highly doubtful, it will then go to the European Parliament.
But if Westminster stops the deal in its tracks, then Brexit could go a number of ways -- including exiting the bloc without a deal at all, or, just possibly, a second referendum that could scrap Brexit altogether.
It would also cast serious doubt on May's future as prime minister, already under intense scrutiny from Brexiteers within her own party unhappy with what they say is a "soft" exit from European regulations.
At a news conference Sunday, Juncker urged UK Parliament to vote for the deal, likely to happen in December. Pointing his finger in the air for emphasis, Juncker told Westminster: "This is the best thing possible for Britain, the best thing possible for Europe...this is the only deal possible."
Meanwhile former UK Prime Minister and pro-EU campaigner Tony Blair had a different take, telling the BBC Andrew Marr Show that a second referendum was "the only way you are going to unite the country."