Rishi Sunak, Britain's former Chancellor of the Exchequer (L) and Britain's Foreign Secretary Liz Truss, the final two contenders to become the country's next Prime Minister and leader of the Conservative party, stand together on stage during the final Conservative Party Hustings event at Wembley Arena, in London, on August 31, 2022. (Photo by Susannah Ireland / AFP)

Foreign Secretary Liz Truss and former Treasury Secretary Rishi Sunak have engaged in a final duel in the race to succeed British Prime Minister Boris Johnson.

Speaking to thousands of Conservative Tory members at Wembley Arena in London on Wednesday, the highly-favored Truss vowed that if she won, she would focus on “energy prices for consumers” and stimulating the economy.

Sunak avoided sharp attacks on Truss and rather differentiated himself from Johnson. He will lead a government “that is run competently and honestly” and that has “decency and integrity” at its core. “This is the change I will bring. This is the Prime Minister I will be.”

The approximately 200,000 members of the conservative Tories will decide on Johnson’s successor at the top of the party in a runoff election that will run until Friday. The winner is to be announced on Monday, who will then take up the office of Prime Minister the following day.

In polls, Truss is well ahead of her rival Sunak. Prime Minister Johnson resigned in early July after an internal party revolt against his much-criticized leadership as party leader. (AFP)