Outgoing UK PM Boris Johnson promises full backing for Liz Truss

New British Prime Minister Liz Truss delivers a speech outside Downing Street in London, on Tuesday, September 6, 2022 after returning from Balmoral in Scotland where she was formally appointed by Britain's Queen Elizabeth II.

Standing outside 10 Downing Street, Britain's new Prime Minister Liz Truss poses for photographers with her husband Hugh O'Leary after delivering her first speech as Prime Minister in central London, on September 6, 2022.

Boris Johnson and his wife Carrie walk away after Johnson delivered his final speech outside 10 Downing Street in central London. Johnson bowed out as British prime minister on Tuesday, ending a tumultuous three years in office and bequeathing his successor Liz Truss a daunting list of problems to tackle.

Boris Johnson delivers a speech outside 10 Downing Street, ahead of officially resigning, in London. Johnson, who was forced out of office by his own Conservative Party over a series of scandals, urged the country to come together and back his successor.

After making a farewell speech outside Downing Street, he left London to travel to Scotland and tender his resignation to Queen Elizabeth.

The 47-year-old Liz Truss is tasked with steering Britain through a looming lengthy recession and an energy crisis that threatens the finances of millions of households and businesses.

Her plan to boost the economy through tax cuts while providing tens of billions of pounds to cap energy costs has already badly rattled financial markets, prompting investors to dump the pound and government bonds.

"This is it folks," Johnson said in his speech. "What I say to my fellow Conservatives, it's time for politics to be over, folks. It's time for us all to get behind Liz Truss and her team and her programme."

Truss will be the fourth Conservative prime minister in six years. She confronts the latest crisis to buffet Britain with a weaker political hand than many of her predecessors after she defeated rival Rishi Sunak in a vote of Conservative Party members by a tighter margin than expected, and with more of her lawmakers initially backing her rival.

Johnson, who fought to stay in office until the end, used his departure speech to boast of his successes, including an early vaccine programme during the coronavirus pandemic and his early support for Ukraine in its battle against Russia.

He urged his ruling Conservative party to put aside their differences to tackle the energy crisis that looks set to dominate Truss's immediate future. "If Dilyn (his dog) and Larry (the Downing Street cat) can put behind them their occasional difficulties then so can the Conservative party," he added.

Truss was announced winner of an internal vote of Conservative party members on Monday, after a gruelling contest that began in July.

Britain's Queen Elizabeth II and Liz Truss meet at Balmoral Castle in Ballater, Scotland, where the Queen invited Truss to form a Government.

In her acceptance speech on Monday, Truss ruled out seeking her own mandate from the public at an early general election, vowing victory in 2024.

Recent opinion polls suggest a sizeable chunk of the British public have no faith in her ability to tackle the cost-of-living crisis. A new poll by YouGov said only 14 per cent expect Truss to do a better job than Johnson.