Allies of Theresa May expect her to resign by the end of the week.

The prime minister is set to meet on Friday with the chair of the 1922 Committee of Conservative backbenchers, Graham Brady, after Andrea Leadsom resigned as the leader of the House of Commons on Wednesday in protest over May's Brexit legislation.

May will meet with Brady after polls close in the European Parliament elections, where May's party is predicted to face a historic defeat.

If May refuses to quit, MPs are preparing to change party rules to force her out.

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LONDON — Allies of Prime Minister Theresa May expect her to announce her resignation by the end of the week after losing the support of senior members of her Cabinet.

Multiple reports suggest May will announce her departure on Friday, after polls close in the European Parliament elections.

"If she doesn't announce a firm date in the near future, she risks the humiliation of the 1922 telling her they are changing the rules and being booted out in a vote of no confidence in a rather undignified way," one friend of the prime minister told Business Insider, referring to the 1922 Committee of Conservative backbenchers.

Another ally of May told The Times that "she thought she had a duty to have one last go, but if that's not going to be possible, then she's out of road."

The prime minister had intended for her government to bring forward her Withdrawal Agreement Bill on Thursday, as voters went to the polls in the European elections.

But Andrea Leadsom, the leader of the House of Commons, who was scheduled to introduce the key piece of Brexit legislation, resigned on Wednesday night in what appears to have been the final blow to May's waning authority.

Several senior members of May's government, including Home Secretary Sajid Javid and Foreign Secretary Jeremy Hunt, had requested to see her to demand that she rip up her Brexit plans. The prime minister refused the meetings on Wednesday but is expected to meet with Hunt on Thursday.

May infuriated Conservative MPs on Tuesday evening by announcing that the House of Commons could vote on whether to hold a new Brexit referendum if it voted for her Withdrawal Agreement Bill.

May runs out of road

Andrea Leadsom. Getty

About 100 Conservative MPs gathered in a committee room in the Houses of Parliament on Wednesday evening to discuss May's future.

Graham Brady, the chair of the 1922 Committee, told them that he would meet with the prime minister on Friday after voting in the European elections concluded.

Conservative MPs emerged from the meeting exasperated at May's refusal to stand down, with one describing the committee as "jellyfish" for refusing to move decisively against her.

"That was a waste of time," one MP who was leaving the room told reporters. "And it will be another waste of time tomorrow, and another waste of time the day after that."

Earlier, committee executives met to vote on whether to change Conservative Party leadership rules to allow a vote of no confidence in May within weeks. The result of the vote will stay sealed in an envelope until Brady has met with the prime minister, according to multiple reports.