UK lawmakers Tuesday endorsed Prime Minister Boris Johnson’s Brexit deal, giving it critical momentum in Britain’s fractious Parliament and raising the prospect that the country’s protracted divorce from the European Union is finally entering its end game.

However, in a sign of the challenges ahead, lawmakers voted minutes later against a proposed timetable to push it through Parliament by the end of the month. Lawmakers said they needed more time to consider the 110-page divorce deal and decide how they might amend it. That represents a setback for Johnson’s oft-stated ambition to pull the country out of the EU by October 31.