Liz Truss becomes UK prime minister after Boris Johnson's resignation

Liz Truss became the prime minister of the United Kingdom on Tuesday, shortly after Boris Johnson formally resigned.

Johnson, who had announced his intention to resign two months ago, formally stepped down during an audience with Britain's Queen Elizabeth II at Balmoral Castle in Scotland on Tuesday morning. A short time later, Truss had her own audience with the 96-year-old queen and was formally asked to form a new government, according to a statement from Buckingham Palace. It was the first time in the queen’s 70-year reign that the ceremonial transfer of power was held at Balmoral, where she is vacationing, rather than at Buckingham Palace in London.

Truss, 47, took office a day after the ruling Conservative Party selected her as its new leader, putting her in line to be confirmed as the U.K. prime minister without the need for a general election because the Conservatives wield a majority in the House of Commons. In a speech following her victory on Monday, Truss said it was an "honor" to be chosen and paid tribute to Johnson, her "friend."

She is the U.K.'s fourth prime minister since 2016 and the country's third female premier ever.

In her first speech from the steps of 10 Downing Street, the prime minister's official residence, Truss once again praised her predecessor as a "hugely consequential prime minister."

"I'm honored to take on this responsibility at a vital time for our country," she said, adding that she was "determined to deliver."

Truss said her three priorities were economic growth, tackling the energy crisis "caused by Putin's war," and improving the National Health Service.

Truss previously served in Johnson's cabinet as the foreign secretary along with Rishi Sunak, the former chancellor of the exchequer whose resignation helped bring about Johnson's downfall earlier this year.

She ran against Rishi Sunak in the Conservative Party's leadership election, in which only the 172,000 dues-paying members were allowed to vote. The party's members cast their votes after eight weeks of campaigning, with Truss -- a supporter of Johnson who said she did not back his resignation -- emerging as the overwhelming favorite.

The campaign was dominated by questions about what either candidate would do to tackle a looming economic crisis, with household energy bills set to skyrocket this winter and inflation -- already reaching a four-decade high at 10.1% -- expected to rise even further, according to the Bank of England. Truss and Sunak clashed most fiercely on the issue of tax, with Truss saying she would not raise taxes while Sunak has supported a windfall tax on energy companies' profits to help ease the burden on households.

Truss has promised action on the energy crisis within a week of taking office, though she has not spelled out her plans in any detail and refused to elaborate when questioned by BBC News on Sunday. She is expected to unveil her plan on Thursday.

Truss will also have the task of uniting a divided Conservative Party. Johnson's tenure in office was dogged by scandal, most notably with the issue of "Partygate," or the illegal gatherings held at government residences while the U.K. was under a strict lockdown amid the coronavirus pandemic. While Johnson's supporters will remember him for securing a huge election victory, Brexit and support for Ukraine, Johnson's detractors say his conduct and flexible relationship with the truth damaged the Conservative Party's brand.

In an op-ed published by The Sunday Telegraph over the weekend, the leader of the opposition Labour Party, Sir Keir Starmer, said that the appointment of a fourth Conservative prime minister in recent years did not mark a "new dawn" for Britain.

"As summer turns to autumn, the shadows of crisis are lengthening, looming over the whole country," Starmer wrote. "There is no sign that either Rishi Sunak or Liz Truss have grasped the scale of what is facing us, let alone possesses the answers to it."

In July, Johnson announced that he had agreed to resign as leader of the Conservative Party, which resulted in his departure as prime minister once the party selected a successor through the leadership election.

"It is clearly now the will of the parliamentary Conservative Party that there should be a new leader of that party and therefore a new prime minister," Johnson said in a July 7 statement delivered outside his office at no. 10 Downing Street in London.

"I want you to know how sad I am to be giving up the best job in the world," he added. "But them's the breaks."