The U.K. and the European Union struck a deal to unlock divorce negotiations, opening the way for talks on what businesses are keenest to nail down—the nature of the post-Brexit future.

The deal, made before dawn on Friday after rushed talks through the night, clears the path to the start of trade talks between the U.K. and its biggest commercial partner. The EU was quick to put down a marker of where it thinks those talks are headed, and it's far short of what May wants.

The agreements outlined on Friday, including a 45 billion-euro ($53 billion) divorce bill and vague promises on the sensitive issue of the Irish border, will come back onto the table if trade talks turn sour. EU officials were already warning that the second phase will be harder than the first, and time is running short before Brexit day in March 2019.