London -- British Prime Minister Theresa May stepped down as leader of her Conservative Party on Friday, formally triggering the race for a successor who will try, where she failed, to deliver Brexit. May will remain prime minister until a new leader is chosen, likely in late July, but will make no further moves on Britain's departure from the European Union.

Brexit is still scheduled for October 31st, but while the contenders thrash it out over leadership of the Conservative Party, the project remains stalled, with the only divorce plan agreed with Brussels rejected by Britain's parliament.

May took office after the shock 2016 referendum vote to leave the EU and has spent the past three years working on a departure plan, delaying Brexit twice to try to get the deal through.

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She finally acknowledged defeat in a tearful resignation speech last month, the culmination of months of political turmoil that had slowly sapped her authority.

"She remains prime minister for a good few weeks yet," May's spokesman insisted, noting that any successor must meet Queen Elizabeth II and assure the head of state that they have the support of enough lawmakers to take over.

She will remain as acting leader of the Conservatives.

Contenders to succeed May

Eleven Conservative MPs have declared their intention to stand to replace Theresa May, including former foreign minister Boris Johnson, but some are expected to drop out before Monday's deadline for nominations.

The winner will have only a few months to decide whether to try to salvage May's plan, delay Brexit again -- or sever ties with Britain's closest trading partner with no agreement at all.

Johnson, a leading campaigner in the 2016 referendum, who quit the government last year over May's plan, is among several would-be candidates who say they are willing to leave the EU without a deal if necessary.

Environment Secretary Michael Gove, another front-runner, is open to another Brexit delay, while Hunt has said leaving with no deal is "political suicide".

Johnson cleared one hurdle on Friday by fending off a legal action brought by a citizen who accuses him of misconduct in public office for making misleading statements during the 2016 campaign about how much money Britain sends to the EU.

Judge Michael Supperstone said the High Court was "quashing the decision of the district judge" to summons the former foreign secretary, bringing an end to the case.

Johnson's lawyers told the court that the earlier ruling ordering him to answer the claims "erred in law" and that the former London mayor was the victim of a "politically-driven process."

Nominations for the Conservative leadership contest open and close on Monday, and the 313 Conservative MPs -- including May -- will hold the first of a series of secret ballots on Thursday.

With the worst performers eliminated each time, the goal is to have two candidates left by June 20. They will then be put to a ballot of an estimated 100,000 party members.

The contest should be completed in the week commencing July 22.