Theresa May will use the remainder of her time as Britain's prime minister to focus on her domestic agenda, her spokeswoman said on Friday, the day May officially steps down as head of the governing Conservative Party.

May will continue to be in office until her party elects a new leader, likely in late July, but has relinquished control over the direction of Britain's tortuous departure from the European Union.

She will exchange letters with the chairs of the 1922 Committee, which groups Conservative lawmakers, later on Friday, the spokeswoman said.

"For the remainder of her time in office, she will be building on the domestic agenda that she has put at the heart of her premiership."

May put on a brave face this week when hosting U.S. President Donald Trump for a state visit, before joining him and other world leaders to mark 75 years since the D-Day landings.

But Trump used the trip to speak with Boris Johnson and other candidates to replace her, emphasizing where the political power in Britain now lies.

"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 monarch they have the support of enough lawmakers to take over.

Brexit is still scheduled for October 31 but while her rivals thrash it out, the project remains stuck, with the only divorce plan agreed with Brussels stuck in Parliament.

May took office after the 2016 referendum vote to leave the EU and has spent the past three years working on the plan, delaying Brexit twice to try to get it through. She finally acknowledged defeat in a tearful resignation speech last month, the culmination of months of political turmoil that has slowly sapped all her authority.

Succession race and power shift

May's stepping down formally triggers the race for a successor who will try where she failed to deliver Brexit.

Eleven Conservative MPs are currently vying to replace her, 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.

Nominations for the Conservative leadership contest must be submitted on Monday, and the 313 Conservative MPs – including May – will hold the first of a series of secret ballots on Thursday.

The selection process should be completed by the end of July.

Former foreign minister Johnson is the favorite to win. He champions a tougher stance on Brexit, saying Britain should leave with or without a deal by the new deadline of October 31, and is trying to persuade Conservatives that he, a former London mayor, is the only candidate who could win a new national election for the Conservative Party.

Other front runners are playing catch up, with the current foreign minister, Jeremy Hunt, and environment minister Michael Gove taking a more moderate stance on Brexit.

(Cover: Theresa May speaks to reporters after being confirmed as the leader of the Conservative Party and Britain's next Prime Minister outside the Houses of Parliament in Westminster, central London, July 11, 2016. /Reuters Photo)

(With input from agencies)