The “moment of truth” for a trade deal between the U.K. and European Union will come in October when the bloc’s 27 leaders will hold a summit and want to see a draft agreement, chief negotiator Michel Barnier said.

That will give time for countries to ratify any agreement before the U.K.’s transition period expires at the end of the year, Barnier said at a European Policy Centre video conference in Brussels on Wednesday.

While there has been little progress in negotiations, Barnier said a deal is still in reach—but warned the U.K. must live up “in spirit and letter” to the commitments it made in the non-binding political declaration in last year’s Brexit deal for there to be a breakthrough.

“We now need clear signals” Britain will do that, Barnier said ahead of another round of talks that starts on Monday. “If we get signals next week and make progress in July, all the better—but it will mean progress on all topics.”

U.K. Prime Minister Boris Johnson has said he sees no reason why a deal can’t be struck in July and doesn’t want talks dragging on after the summer. London has rebuffed the EU’s demands for the same fishing rights it enjoys today and for a level playing field for business that would keep Britain aligned to some of the bloc’s rules.

Barnier said the ball is now “in the U.K.’s court,” but both sides will need to compromise.