LONDON — British Prime Minister Theresa May began reshuffling her leadership team Monday in a bid to reboot her Conservative Party after a bungled election last year.

But the reorganization quickly became more remarkable for what May didn't do rather than what she did, highlighting the difficulties imposed by Brexit and the erosion of the prime minister's authority since the ill-judged vote in June that cost her party its parliamentary majority.

There were a few top-level changes. Immigration Minister Brandon Lewis, for instance, was appointed Conservative Party chairman, a role that includes the day-to-day running of the party. Education Secretary Justine Greening quit the government, after refusing to take a new post, and was replaced by Damian Hinds.

But all the big beasts — as the British media and commentators call political heavyweights — kept their jobs. Foreign Secretary Boris Johnson, Chancellor of the Exchequer Philip Hammond, Home Secretary Amber Rudd and Brexit Minister David Davis all stayed put.

"Clearly, she's keen to put her stamp on the party and do the things you try to do with reshuffles — bring through new talent, make the party more representative — but she's very constrained," Rob Ford, a professor of political science at the University of Manchester, said of May's decisions.

One constraint is keeping the delicate balance in May's top team between those who supported the "leave" agenda and those who backed "remain" in Britain's referendum on whether to stay in the European Union.

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Another, Ford said, is the risk of "potentially mobilizing any of the big beasts." He added: "It's the old Lyndon Johnson adage. I'll avoid the ruder version. You want them inside the tent weeing out, not outside the tent weeing in."

May called last year's general election in hopes of strengthening her hand ahead of all-important Brexit negotiations. Instead, her Conservative Party now has to rely on Northern Ireland's Democratic Unionist Party to pass key legislation.

The reshuffle was prompted in part by the ousting of Damian Green, May's deputy and the de facto deputy prime minister.

Green was forced to step down after he made misleading statements about pornographic images found on his computer. David Lidington, the justice secretary, replaced Green on Monday but was not given Green's title of first secretary of state.

In a surprise development, James Brokenshire, a longtime ally of May's, resigned from his post as Northern Ireland secretary, citing upcoming lung surgery. Karen Bradley, the culture secretary, replaced him.

Theresa May’s horrible, no good, very bad day

The reorganization will extend through Tuesday, when there could be a clutch of new mid-ranking ministers, commentators said. According to analysts, the party could promote a younger generation of politicians to try to lure some of the youth vote that has gone to the opposition Labour Party.

The top-level changes announced Monday did not happen without an embarrassing gaffe. The reshuffle began when the Conservative Party's social media team tweeted congratulations to Transport Secretary Chris Grayling on his appointment as the new Conservative Party chairman.

The tweet was quickly deleted, and it was announced shortly afterward that the job would in fact go to Lewis, the immigration minister.

"That reign of Conservative Party chairman lasted about 37 seconds," noted Sky News's Faisal Islam.

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Today's coverage from Post correspondents around the world

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Today's coverage from Post correspondents around the world

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