What to Expect as the U.K. Changes Prime Ministers

When there is a clear opposition victory in Britain, the transition of power takes place with ruthless speed.

The Cabinet Manual, which sets out the official guidance on the process, says that “the incumbent prime minister and government will immediately resign and the sovereign will invite the leader of the party that has won the election to form a government.”

“Immediately,” in practice, means Friday morning. The result in Prime Minister Rishi Sunak’s own constituency in northern England, where he held on to his seat, was announced shortly before 5 a.m. local time. He was on a flight back to London not long afterward.

Departing prime ministers traditionally pose with their families for a final set of photographs in Downing Street, their home and workplace while in office.

Mr. Sunak is then expected to give one last speech in Downing Street, around 10:30 a.m. local time (5:30 a.m. Eastern).

After that comes a short drive to Buckingham Palace, usually trailed by news helicopters, to resign in a private meeting with the monarch, now King Charles III.

The next prime minister, Keir Starmer, is likely to be close behind. In 2016, according to the House of Commons library, the car of the incoming leader, Theresa May, arrived at the palace 32 seconds after her predecessor, David Cameron, had left.

A new leader’s appointment also takes the form of a private meeting with the king, usually right after the resignation. It’s known as “kissing hands,” though it involves little ceremony and no kissing.

Expect a photographed handshake, followed by another prime ministerial speech in Downing Street, this one by Mr. Starmer. That’s expected around 12:20 p.m. local time.

Standard practice is for the new prime minister to move into No. 10 Downing Street more or less immediately, applauded by the permanent civil service staff on arrival.

Mr. Starmer will then appoint other ministers. There is not usually much suspense: British opposition parties maintain a “shadow cabinet” of candidates for government positions. Labour has told British news outlets that Mr. Starmer expects to announce his full cabinet by about 8 p.m. (3 p.m. Eastern).

More junior appointments are expected to follow on Saturday, with an afternoon pause while the England men’s soccer team plays Switzerland in the quarterfinals of the Euro 2024 tournament.