Former Commons leader Penny Mordaunt said the Conservative Party lost the general election because it had stopped being seen as honourable and trustworthy.
Ms Mordaunt, who lost her Portsmouth North seat at the election after 14 years in July, said the Conservative Party had moved too far away from the core beliefs of British people which it had once shared.
Speaking from the stage in the main hall at the Conservative Party Conference in Birmingham, Ms Mordaunt said: “We value courage, endeavour, enterprise, service and duty, creativity and discovery, competence and skill, grit, determination, kindness, tolerance and freedom, cheerfulness, honour, valour, graft, integrity, trust.
“It was our belief in those values that enabled our greatest deeds and victories, and not just those at the ballot box.
The former cabinet minister, who served as defence secretary and international development secretary under Theresa May, said the party needed to have its soul restored as it aims to bounce back from the historic defeat.
She is leading a Conservative Party programme to recruit more members and work closer with its grassroots.
She said: “We will need the largest outreach programme any party has undertaken, and that is what I will prepare.
“Will you help restore the soul of this party, to place Britain’s values back at the heart of everything we do to earn back trust, approval from the public, and perhaps even pride? For without that, no policy or personality will matter.
“Do this well, then when the nation goes looking for those in tune with its values again, we will be there.”
Ms Mordaunt was once seen as a potential future Conservative Party leader, and twice stood unsuccessfully to take charge of the party. She lost to Liz Truss in 2022 and Rishi Sunak later in the same year.
She was critical of Prime Minister Sir Keir Starmer, and compared part of his 12-week tenure leading the country to that of corrupt former Filipino politician Imelda Marcos.
Ms Marcos was sentenced to six to 11 years in prison for seven counts of violating an anti-corruption law when she illegally funnelled about £152 million to Swiss foundations in the 1970s as metropolitan Manila governor. She has since sought to appeal against the verdict, with no resolution found.
Ms Mordaunt said Britons’ values meant they were already concerned about the conduct of Sir Keir, who has faced scrutiny over donations he has taken since being elected Labour leader in 2020.
She told the conference: “The good news is that the belief in those values … is now causing them to feel a little bit icky about their new prime minister.
“A chap who in a mere 12 weeks has brought doubt to our economy, fear to our elderly, a touch of the Imelda Marcos to the office of prime minister, and sausage memes to our timelines.
“They are right to be iffy about him.
“It’s not Britain that needs to find its way back to us. We must find a way back to those we serve.”