London - With British Prime Minister Theresa May clinging to power amid a rebellion over her Brexit strategy, a number of potential scenarios open up although analysts agree that the prospect of a leadership contest is unlikely for now.

- Rebellion stalls, uneasy Brexit unity -

May on Monday swiftly replaced her outgoing Brexit minister David Davis with another Brexiteer, and foreign minister Boris Johnson with former "Remain" supporter Jeremy Hunt.

With remaining ministers, including prominent Brexiteers, taking to the British airwaves to extol the compromise agreement, May appears to have weathered the immediate storm.

"My impression is that this is probably as far as it (rebellion) goes -- I can't see more ministers resigning," said Simon Usherwood, at politics professor at the University of Surrey.

He predicted backbench Tories would let May be responsible for a softer version of Brexit "to get over the line of leaving next March, and then replace her in April".

Polly Mackenzie, director of the cross-party think-tank Demos, agreed Brexiteers simply do not appear to have the numbers to oust May or force through their preferred plan.

"I just don't see them doing it," she said of the Conservative rebels. "I think they're pretty confident they'd lose so all that does is strengthen her hand."

- May challenged for leadership and wins -

May's Conservative opponents could trigger a confidence vote against her if at least 48 MPs write letters of no-confidence to the party's powerful 1922 Committee, which initiates any leadership challenge.

With dozens of Tory lawmakers backing a hard Brexit, they may have the votes to force a contest -- but likely lack the numbers to formally force her from office.

May has vowed to fight any challengers and at least 159 lawmakers would have to vote against her -- a figure hardliners may struggle to reach.

"They want to stick with her because for the first time since the (2017) election she's actually acted like the prime minister," said Mackenzie, referencing May's new take-it-or-leave-it style in cabinet last week.

Withdrawal from the European Union

Any leadership contest would bring Brexit negotiations with the EU to a temporary standstill, increasing the possibility of extending Britain's withdrawal date beyond March, 2019.

And even a victorious May would be unlikely to have strengthened her negotiating hand, Mackenzie added.

"I don't think anything that we do in Britain changes the way the leaders of the European Union think the (EU) should operate," Mackenzie said, noting it will likely reject May's plan to fragment the single market.

"The founding principles of the EU are a lot older than Theresa May's cabinet and its foibles."

- May challenged for leadership and loses -

Political observers have speculated that if Tory rebels mustered around 100 no-confidence votes, May's authority could be so weakened she would still have to resign.

However, few colleagues have shown a willingness to challenge her publicly -- except Johnson.

Usherwood believes the now-former foreign secretary is "the pivotal person in this because he can do a lot of stirring".

"He still has the capacity to be very disruptive and I don't know what his thinking is. It may be clear in the next day or two, it might not."

However, any new leader would be similarly constrained by Britain's tortuously divided parliamentary arithmetic over Brexit and the EU's red lines, he added.

"Clearly there will be a degree of contingency planning about who the different candidates might be and what they might want," Usherwood said of the EU.

"Any delay now for any reason just will strengthen the (EU) Commission's separate work on no-deal contingency planning."

- Second referendum or a general election -

An unlikely course of action is that Theresa May orders a referendum or general election to try to win popular backing for her Brexit plan.

But haunted by the unexpected results of the 2016 poll and last summer's disastrous decision to hold a snap contest, which resulted in May losing her parliamentary majority, the odds of reruns are "slim", according to Mackenzie.

"A general election now could completely destroy any chance of Brexit and it could install (Labour leader) Jeremy Corbyn in government," she said. "So none of those MPs are going to vote for that."

Nonetheless, British bookmakers slashed the odds of a 2018 election this week amid the fevered political temperature, while backing for another people's vote on Brexit has been gaining support.

As with most scenarios, either option would leave the EU waiting on the sidelines wondering what Britons will decide.

By Joe Jackson