British Prime Minister Theresa May is preparing to shuffle her Cabinet as she tries to bolster her authority ahead of a crucial new phase in Brexit negotiations.

May said she will re-jig government ranks “soon,” with changes expected as early as Monday.

She did not indicate which ministers are set to lose their jobs. The Sunday Times reported that several senior ministers will stay in their posts, including Foreign Secretary Boris Johnson and Brexit Secretary David Davis.

May’s grip on power was weakened by her Conservative Party’s poor showing in a June election, which saw it reduced to a minority government.

She also lost a key Cabinet ally before Christmas, when deputy premier Damian Green was forced to resign for making misleading statements about pornography found on his office computer.

But the embattled British leader got a boost last month when the European Union agreed that talks on the U.K.’s departure had made enough progress to start discussing future trade relations.

May told the BBC in an interview broadcast Sunday that she hoped to secure agreement with the EU on a post-Brexit transition period by March 31, and to draft a withdrawal agreement by the end of 2018.

Britain is due to leave the EU on March 29, 2019. May’s chances of staying in power depend heavily on her ability to secure a smooth exit and a good free-trade deal with the bloc.

May said she would remain in office “as long as people want me to serve,” and hoped to lead her party into the next election, due by 2022.

“I’m not a quitter. I’m in this for the long term,” May said.

(AP)