Voting closed Monday in the two-man contest to become Britain’s next prime minister, as critics of likely winner Boris Johnson condemned his vow to take the UK out of the European Union with or without a divorce deal.

Members of the governing Conservative Party had until 5 pm (1600 GMT) to return postal ballots in the race between Johnson and Foreign Secretary Jeremy Hunt to lead the party and country.

The winner will be announced Tuesday and take over from Prime Minister Theresa May the following day.

Johnson, a populist former mayor of London, is the strong favorite.

Several members of May’s government have said they will resign before they can be fired by Johnson over their opposition to his threat to go through with a no-deal Brexit if he can’t secure a renegotiated settlement with the EU.

Most economists say quitting the 28-nation bloc without a deal would cause Britain economic turmoil.