Boris Johnson weighs how to challenge Theresa May

On Friday, UK Foreign Secretary Boris Johnson congratulated Theresa May for taking a decision on how to proceed with Brexit. On Monday, he resigned in protest.

The change of heart was so fast that Mr. Johnson does not seem to have a short-term plan, although other Brexiters take heart as a result of his decision.

In the coming months, Mr. Johnson could pose a serious threat to Ms. May from the back benches, undermining her in the final months of negotiations with Brussels. George Osborne, the former Chancellor, described Johnson as being in a "permanent leadership campaign".

Johnson's hand appears to be forced by the resignation of his cabinet colleague, Brexit Secretary David Davis, on Sunday night and by the outrage of Eurosceptic deputies at Ms. May's plan.

But former foreign affairs allies insist that he was always "deeply unhappy" about Ms. May's proposals, decided to resign Saturday and simply took the week-end to confirm his decision.

Downing Street had asked Mr. Johnson to give his name to an article of opinion with Chancellor Philip Hammond, which the Minister of Foreign Affairs had refused to do. "He would have walked anyway," said one.

million. Johnson confirmed his decision to his three closest advisors on Monday morning, and spent the day joining them at his official residence at Carlton Gardens, writing a resignation letter.

The harsh Brexiters now urge Mr. Johnson to fight Ms. May, and those who are loyal to the Prime Minister are preparing for the days to come.

A former leave activist said that Johnson and Jacob Rees-Mogg "should challenge" Ms. May about Brexit. "She is not going to change the policy herself."

But Mr. Johnson has a diminished band of followers. Unlike Mr. Osborne or Ms. May, he did not form a coterie of loyal councilors and young deputies. One of the three councilors with him Monday, Ben Gascoigne, has already decided to leave him.

Guto Harri, a former advisor to Mr. Johnson at City Hall, said the former Foreign Minister "would run a grave danger of becoming the old boxer too desperate not to come back in the ring while it should not ". A leadership challenge could be a "sorry look," he added.

Expectations are low. A Brexiter MP, who wants Ms. May to resign, said that a failed leadership challenge was "all on the Downing Street Grid", referring to the system used to plan the news.

Another leave activist said that he was waiting for Mr. Johnson "to rest" and wait for the prime minister "to retrograde on free movement [of people]."

And another said that Mr. Johnson could become "a distant personage rather quickly". "He's an endearing guy, but he's had problems in recent months," he added. He will fail [in a leadership challenge]. "

Most Conservative MPs were originally supporters of Rest, and although a large majority is now reconciled with Brexit, they are more likely to favor Ms. May's moderate version." Johnson's

Mr. Johnson has already left many opportunities to challenge Ms. May for leadership.

He could have stayed in the running in July 2016 after Michael Gove withdrew his support. He could have resigned as Foreign Secretary on at least four occasions: in June 2017, after the Conservatives lost their majority in the early elections, in September 2017, when he wrote a scathing page of the Daily Telegraph on Ms. May's Brexit strategy, in October 2017, when some Conservative MPs asked Ms. May to resign after a disastrous speech at the conference, or in June 2018, when The government held a parliamentary vote on the expansion of Heathrow Airport, which it had vowed to oppose.

Whenever Mr. Johnson resigned. After early election, he sent a message to a group of WhatsApp MPs, praising Ms. May's "extraordinary qualities." After the Telegraph article, he finally backed up his Florence speech.

After his performance at the conference, he praised her for "putting housing at the heart of the revival of the British dream". And while Parliament was voting on Heathrow, he organized an impromptu diplomatic trip to Afghanistan.

Up to now, Johnson's allies have refused to say he was going to launch a leadership offer.

His immediate concern may be finding a place to live: he lived at the official residence, and his family home in Islington is rented. He retains a property in his former constituency of Henley.

A key consideration for Mr. Johnson is that the first person to challenge Ms. May will almost certainly carry the wrath of MPs. Michael Heseltine, the pretender for the post of prime minister in the late 1980s, helped overthrow Margaret Thatcher, but did not get the job for himself.

million. Johnson was to host a summit of the Western Balkans this week, paving the way for other countries to join the EU. He was also invited to a dinner with Donald Trump, which he should not attend.

On Tuesday, Trump called the former foreign minister "friend" who had been "very supportive". The starring call of Mr. Johnson lasts at least with the US President, if not with Westminster.