Little-known Penny Mordaunt ready to run again for Britain's top job

When Liz Truss was asked to come to parliament to explain the sacking of her good friend and finance minister, she sent Penny Mordaunt in her place, offering her potential successor a primetime opportunity to flex her political muscle.

In what only underlined the dwindling fortunes of Truss, Mordaunt took the lead role on Monday to explain why her boss had sacked Kwasi Kwarteng and replaced him with former health minister Jeremy Hunt who ripped up much of her economic plan, Reuters reports.

"The prime minister is not under a desk," Mordaunt said in parliament, keeping a straight face despite the jeers and laughter from the opposition Labour Party facing her.

"I can assure the House (of Commons) that ... with regret, she is not here for a very good reason."

In a speech praised by some of her colleagues as showing the necessary mettle to be a strong prime minister, Mordaunt calmly batted away the mocking of the Labour Party, including its leader Keir Starmer who said: "I guess under this Tory government, everybody gets to be prime minister for 15 minutes."

A Royal Navy reservist, Mordaunt, 49, has navigated the tenures of the four prime ministers she's served under, keeping her distance from Boris Johnson's scandal-ridden time in power and staying in the cabinet under Theresa May to make her support for Brexit felt.

Under Truss, she was appointed leader of the House of Commons, a role which also by chance gave her a higher profile job as 'Lord President of the Privy Council' - meaning she presided over the formal announcement of Queen Elizabeth's death and the proclamation of the new King Charles.

Mordaunt now has her second chance to run for the top job, after just missing out on the final two in the contest to become the leader of the ruling Conservative Party earlier this year. That race saw Truss defeat former finance minister Rishi Sunak.

Then, Mordaunt promised to rely more on her cabinet team of top ministers, breaking with what some Conservatives felt became the "Boris show" in Number 10 Downing Street under Johnson.

She also promoted her patriotism, talking about her memories of the Falkland conflict that helped to define former prime minister Margaret Thatcher.

"Recently, I think we've lost a sense of ourselves," she told supporters at her first leadership launch on July 13.