A momentous day in British politics as Boris Johnson becomes Prime Minister.

Earlier in the day, Theresa May attended PMQs, a long session even by recent standards, as the Commons said farewell. There followed a short statement as May left Downing Street, reflecting on her fraught three-year premiership, thanking the British people “for the chance to serve.” Then is was to see the Queen, and a recommendation to invite Boris Johnson to form a new government.

The new Prime Minister entered No. 10 a few moments ago, his new home and office. The political appointments will be made in the next hours and soon full ministerial teams will be in place, reward for a mix of vocal supporters and political allies. Remainers are out.

In Downing Street, the Prime Minister made a short statement, speaking to his “friends” in the EU, Ireland and to the public. He stressed that he is fully determined to take advantage of Brexit and to take on the detractors, saying that “the people who bet against Britain are going to lose their shirts.”

“We are going to come out of the EU, no ifs or buts.” He also spoke of a new and exciting partnership with the European Union. Preparing for a post-Brexit future: “The time has come to act.”

The union, infrastructure, adult social care, education and police numbers all featured in his statement.

“My job is to serve you, the people.” Ending that: “we will work flat out to give the country the leadership it deserves.”

Yet earlier a flutter of resignation letters came from Chancellor, Philip Hammond, International Development Secretary, Rory Steward, Justice Secretary, David Gauke and others. Sign of how divided the party is, and the size of the new PM’s problems on the backbenches. The Brexiter European Reform Group replaced as detractors by those who will do anything to stop a no-deal Brexit.

The Prime Minister faces the most complex political crisis to affect Britain since 1945. He does so with many opponents, not least from his own benches, an almost non-existent parliamentary majority, and an almost impossible deadline to extract the UK from the European Union by the end of October.

The first staffer appointments to Downing Street are unequivocally Brexiters, Dominic Cummings chief among them. The appointments to cabinet will start this evening, as we predicted on Monday, expect top jobs for Dominic Raab, Michael Gove, Priti Patel and Sajid Javid.

Johnson’s popularity is built on emotional appeals. He defied his background and critics to be elected Mayor of London, twice. He was a principal voice to carry Britain to Brexit, bringing swaths of England’s working north with him. And, critically, convinced members of the 1922 committee to put him on the final ballot for the party’s leadership. The calculation then was, without major mistake or embarrassment the membership at large would elect Johnson, that came true yesterday wining 66 per cent of the votes cast.

In the side lines of today’s emotion and ceremony, the Labour leader called for a general election, we’ll hear more of “no mandate from the general public” in the coming weeks.

The former Conservative Prime Minister, John Major said that Johnson: “must choose whether to be the spokesman for an ultra-Brexit faction, or the servant of the nation he leads. He cannot be both.” This will be the early test of his premiership. He long coveted the top job, we will soon know what sort of Prime Minister Boris Johnson will really be.

The now backbench MP for Maidenhead said in the Commons earlier: “We are living through extraordinary political times” – indeed we are, there will be more to follow from H+K London’s Political + Public Affairs team, on the new government and the opportunities to engage.