By Elizabeth Piper, Alistair Smout and Andrew MacAskill
LONDON (Reuters) - 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.
"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 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's 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.
Largely unknown outside Westminster prior to taking an early opinion poll lead among Conservative Party members earlier this year, the public might have first seen Mordaunt on the reality TV show Splash! in 2014, where celebrities learnt to dive. She performed a belly flop.
She also peppered a speech in parliament the year before with the word "cock" as part of a bet with her friends, much to the delight of other lawmakers.
But earlier this year, as she became tipped to replace Johnson, Mordaunt was soon the target of criticism in the media and from some of her colleagues.
Former Brexit negotiator David Frost said Mordaunt did not "master detail" and the Daily Mail quoted an unnamed minister as saying "she's lazy".
A source from her campaign responded to Frost's remarks by saying: "Penny has nothing but respect for Lord Frost."
But a tweet on Mordaunt's account, swiftly deleted by her team, was published the day of the vote saying that any Conservative lawmaker voting for Sunak or Truss would "murder the party you love", undermining her pledge to campaign cleanly.
Mordaunt was born in Devon in the southwest of England in 1973, the daughter of a soldier and a teacher.
The family moved to Portsmouth when she was young and she has recalled watching soldiers in ships set off to fight for the Falklands: "It taught me that my country stands up to bullies."
She lost her mother to breast cancer at 15, taking on the role of helping two brothers, while her father was also diagnosed with cancer the following year.
"It was pretty relentless in terms of stresses and losing a parent, you're trying to deal with all of that and study, run a house, look after two brothers," she told the Sunday Times in 2019.
After finishing school, Mordaunt worked in a Romanian orphanage after the country's 1989 revolution, which she cites for prompting an interest in politics, and at university, she covered some of her costs by working as a magician's assistant.
Early jobs included working as a press officer for former Conservative leader William Hague and as head of foreign press for George W. Bush's successful 2000 U.S. presidential campaign.
Mordaunt was elected to parliament in 2010 for Portsmouth North and swiftly became a minister. Her first post came as a local government minister in 2014, followed by armed forces minister and disabilities minister.
She joined May’s cabinet in 2017 as international development minister but a stint as defence secretary lasted just 85 days, when she was sacked by Johnson, reportedly for backing Hunt in his leadership campaign. Johnson eventually brought Mordaunt back into government in February 2020.
Truss appointed Mordaunt as the leader of the House of Commons, charged with setting out the government business with her no-nonsense attitude gaining admirers.
"She has broad appeal," one veteran Conservative said early in the campaign, referring to Mordaunt's ability to find friends in the various tribes of the Conservative Party, whether they are eurosceptics or so-called one-nation Conservatives.
But her understated approach can cause problems. Some of her allies say she is too slow to take credit for her achievements, while others say she is too far to the left of the party.
But Mordaunt's team was convinced earlier this year that only she could beat Labour at the next national election.
"Not every candidate would win an election, but time and time again the polls show that Penny is the candidate Labour fear the most," one campaign source said.
(Reporting by Elizabeth Piper; Editing by Alison Williams and Andrew Heavens)