The candidates for the Conservative leadership have not acknowledged “how bad things are in the country” and the Tory party, according to former prime minister Liz Truss.

Ms Truss said the four MPs vying to be Rishi Sunak’s successor have to “explain what went wrong”.

Kemi Badenoch, Robert Jenrick, Tom Tugendhat and James Cleverly are trying to drum up support from their colleagues and party members at the Conservative Party conference in Birmingham.

Speaking at an event at the conference on Monday, Ms Truss also said she thought the party would have fared better in July’s general election if she had still been leader rather than Mr Sunak.

She told the in-conversation event: “So far, I haven’t seen any of the candidates really acknowledge how bad things are in the country as a whole, and frankly, for the Conservative Party.”

“They think ‘all we need to do is show competence and we will be ushered back into office’,” Ms Truss said, adding: “They have to explain what went wrong, why things are so bad for the Conservatives and what they’re actually going to do.”

The first of the leadership candidates got their chance to address members from the conference’s main stage on Monday afternoon.

Mr Tugendhat was the first up for his interview session, and told delegates that the party had to “rebuild” trust.

The enemy is trust. We have eroded trust in ourselves and we need to rebuild trust in the Conservative Party

The Conservatives won 121 seats at the general election in July, down hundreds on their 2019 election results.

Asked whether the Liberal Democrats or Reform UK were the biggest enemy facing him, Tonbridge MP Mr Tugendhat said: “The enemy is trust. We have eroded trust in ourselves and we need to rebuild trust in the Conservative Party.

“Let’s be honest: people didn’t vote for that paddleboarder (Sir Ed Davey) to become prime minister and they didn’t vote for Nigel (Farage) either to become prime minister.

“They voted against us. People woke up in the morning and they wanted to get us out.”

Ms Badenoch, who appeared on stage not long after her rival, said she did not want to see the Tories die after the bad results at the general election.

She said she could “help sell conservatism to get confident conservatism” and ruled out an electoral pact with Reform UK if she wins the leadership contest.

The North West Essex MP said that she would work with Mr Farage’s party on Bills in Parliament, but added: “Anyone who’s not a Conservative has got to be defeated. For what it’s worth I don’t believe that Reform are real Conservatives.

“They, like the Liberal Democrats, are not serious people. And by that I mean the Reform politicians.”

Migration, the NHS and the future of the Conservative Party are among the topics the leadership candidates are discussing with members at the Birmingham gathering.

Mr Jenrick has said he wants to “get migration done”, echoing former leader Boris Johnson’s language on Brexit.

Former immigration minister Mr Jenrick – who quit Mr Sunak’s government after pushing for tougher measures over the Rwanda asylum scheme – is advocating for a cap on legal migration in the tens of thousands or fewer and for a stronger version of the Rwanda policy.

He told a breakfast rally on Monday morning: “If we have that cap, then we can stop talking about migration.

“I want to get migration done.

“This is a running sore in British politics.

“It’s important that we settle this by having serious answers to these challenges.

“Then we can talk about all the other issues that the public wants us to be discussing, like the economy and the NHS.”

However, Mr Cleverly said that those offering a simple solution to tackling migration “don’t know what they are talking about”.

Reflecting on his time as home secretary, he said that “under my watch” the “asylum rejection rate went up, our deportation rate went up, our net migration came down”.

Mr Cleverly added: “I gobbed off less and delivered a bucketload more.

“That is what gets us back into office, and anyone who sits here in front of you or on a stage wherever and says the simple solution is to do this one thing, they either don’t know what they are talking about or they hope you don’t know what you are talking about.”

The Braintree MP also said the Tories need to stop “behaving like bloody children” in order to win back the trust of voters, and urged the party not to become the “marketing department” of rival party Reform UK.