- Boris Johnson has won the contest to become Conservative party leader and UK prime minister.
- He is set to officially become prime minister on Wednesday.
- The process of Johnson replacing Theresa May will take place over a flurry of events before Parliament breaks up for summer recess on Thursday.
- A number of ministers have already resigned from government.
- Here’s how it will all work.
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Boris Johnson has won the race to become the United Kingdom’s new prime minister.
The Conservative party’s 1922 committee announced on Tuesday morning that Conservative party members had voted for Johnson to succeed Theresa May as their party leader and prime minister.
He comfortably defeated rival Jeremy Hunt, winning around 66% of the vote.
However, Johnson is not quite prime minister yet. This won’t be official until flurry of events takes place today.
Here's what happens now that Johnson won the Conservative party leadership contest.
Theresa May takes her last Prime Minister's Questions
Wednesday will be a very hectic day in British politics.
It is set to kick off with outgoing prime minister May taking part in her final Prime Minister's Questions.
You can expect her to make a short farewell statement to the House of Commons. Departing prime ministers usually receive a standing ovation from Members of Parliament once their speech is over.
You can also expect MPs on all sides to put aside their criticisms of May - of which they have previously had many - and say some nice things about her before she leaves the House of Commons as prime minister for the final time.
May says goodbye to her staff and the nation
May will then head back to 10 Downing Street where she will say thank you and good bye to her staff before making a final statement as prime minister on the steps outside.
Her farewell statement is expected to take place at around 14:00 (BST.)
May tells the Queen that Johnson is ready to be prime minister
She will then rush off to Buckingham Palace and advise the Queen that she is resigning as prime minister and handing over to Johnson. This is a constitutional requirement for the anointing of a new prime minister and is almost always a formality.
May is then expected to return to Maidenhead constituency.
Resignations
While the main action unfolds at Buckingham Palace, we will probably see more current government ministers announce their resignations.
Conservative MP Margot James quit as a junior minister last week in order to vote for legislation designed to prevent Johnson forcing through a no-deal Brexit. She predicted that more ministers would resign before Johnson officially becomes prime minister.
Foreign Office minister Alan Duncan quit on Monday.
Education minister Anne Milton was the first minister to quit on Tuesday, saying she had "grave concerns about leaving the EU without a deal." Justice Secretary David Gauke announced his resignation as Johnson took to the stage to deliver his victory speech.
International Development Secretary Rory Stewart followed shortly after.
Other ministers who oppose a no-deal Brexit could quit on Wednesday, including Chancellor Philip Hammond. As many as five ministers could resign before Johnson is officially anointed, according to reports.
Johnson goes to Buckingham Palace for the 'kissing of hands'
Johnson will then travel to the Palace to meet the Queen and tell her that he can form a government. He will arrive at the Palace at around mid-afternoon.
This is often described as the "hand-kissing" moment, although previous prime ministers have reported that their lips are required to merely brush the monarch's hand rather than kiss it.
Read more: The Queen is being dragged into Britain's Brexit crisis
Johnson enters Downing Street as prime minister for the first time
The MP for Uxbridge and South Ruislip will then head to 10 Downing Street and make his first statement to the nation before entering the building as prime minister for the first time.
It is not yet clear whether he will enter alongside his current partner, Carrie Symonds.
There have also been reports that Johnson will ditch the lectern which prime ministers usually use when speaking outside 10 Downing Street.
Once insider 10 Downing Street, he will be introduced to his new members of staff.
He will also be given an immediate security update on the main threats to the UK.
What's not widely-known about a prime minister's first day is they also must write "letters of last resort" to UK military chiefs, instructing them what to do if the UK government is wiped out in a nuclear attack. It's probably the biggest decision Johnson will ever make in his life.
Johnson hires and fires to form his Cabinet
The new prime minister will then return to his parliamentary office and begin the process of filling ministerial positions in his new government.
Johnson will have one-on-one meetings with Conservative MPs to let them know that they have either been promoted, demoted, hired, of fired altogether.
Ex-Cabinet ministers Gavin Williamson, Dominic Raab and Andrea Leadsom are all expected to return to senior government positions. Home Secretary Sajid Javid and Chief Secretary to the Treasury Liz Truss are the leading candidates to be Chancellor. Environment Secretary Michael Gove could also be line for a promotion.
Johnson is set to appoint the highest ever number of ethnic minority minsters, The Times reports. The newspaper adds that Priti Patel is in pole position to be Home Secretary.
Another big questions is whether Johnson will opt to keep leadership rival Jeremy Hunt in his post as foreign secretary.
The identity of Johnson's chief whip has already been revealed. It will be Mark Spencer, an MP virtually unknown by the public but who is widely-respected in the Conservative party. Party discipline will be of critical importance in the coming months, with the Conservative government's majority wafer-thin and set to get even smaller.
Johnson's new prime ministerial team will announce a number of appointments throughout Wednesday evening and on Thursday too.
Phone calls with world leaders
Johnson will probably spend some of time this evening fielding congratulatory phone calls from world leaders.
One of the first calls he is likely to receive will be from US President Donald Trump, who has repeatedly expressed his admiration for Johnson and whom Johnson has spent a great deal of time seeking to woo. Trump on Tuesday said Johnson was "smart," "tough," and welcomed his victory as "Britain Trump."
READ: Donald Trump welcomes Boris Johnson's victory as the 'Britain Trump'
However, with Brexit looming, Johnson can also expect prompt calls from European leaders including German Chancellor Angel Merkel - who he has previously compared to a Stasi officer - and French President Emmanuel Macron - who he described as a "jumped-up Napoleon."
Prime Minister Johnson addresses Parliament
Thursday will kick off with the newly-anointed prime minister addressing MPs in the House of Commons.
The statement - expected at around 11.00 (BST) - will be Johnson's only House of Commons address before Parliament breaks up for its annual summer recess.
You can expect a febrile and noisy atmosphere in the House of Commons while Johnson addresses MPs as prime minister for the first time.
Johnson's Cabinet is confirmed
There will be then be a privy council meeting at around 16:00 (BST) where members of Johnson's new-look Cabinet will be officially sworn in. There will be an official photo taken.
Johnson's government begins
Once Johnson has assembled his team and spoken to key world leaders, the tricky business of governing the UK with a wafer-thin parliamentary majority will begin.
At the top of his in tray will be Brexit, with just three months to go until the UK is due to leave the European Union. The ongoing Iran crisis will also feature high up on his immediate to-do list.
Read more: The 5 big problems Britain's next prime minister will have to deal with on his first day