Kemi Badenoch has hit back at her Tory leadership rival Robert Jenrick’s claim that her decision not to set out detailed policies was “disrespectful” to the party’s membership.

Speaking to Political Thinking with Nick Robinson, Badenoch said she would not use that word about another candidate and that everyone had “their own campaign approach”.

“If this was a general election, yes, it would be wrong to be standing with no policies. This is not a general election,” she told Nick Robinson.

She added: “He [Jenrick] doesn’t know what he’s going to be standing on in four years’ time.”

Jenrick stood by his criticism in an interview with BBC Radio 5’s Matt Chorley.

“Kemi and I disagree on this point. I believe you have to start with principles and values, but I think that is not enough. You also have to have policies.”

He argued that the public were “deeply sceptical” of politicians and the best way to win them back was to set out policies and “lay out the trade-offs”.

“The age of policy-free politics is over,” he said, adding that it was “wrong” to ask party members to support you “on the basis of a plan for tomorrow”.

During the leadership campaign, Jenrick has said he wants to leave the European Convention on Human Rights, encourage housebuilding and oppose Labour’s plans on reaching net-zero carbon emissions.

Defending her approach, Badenoch said the party members know what her principles are. She said she would take time to design policies adding: “We have time, we don’t need to rush.”

She said she would never make a promise “unless I know how I am going to deliver it”.

Earlier in the week, Jenrick told BBC Radio 4’s Westminster Hour: “I think it’s disrespectful to the members and the public to ask for their votes without saying where you stand on the big issues facing our country today.”

Conservative Party members are currently voting between the two candidates and a result is due on 2 November.

Unlike her rival, Badenoch has not done many media appearances, however in a wide-ranging interview she spoke to Nick Robinson about her thoughts on net-zero, immigration and Covid lockdowns.

On the environment, she said she was a “net-zero sceptic” but not “a climate change sceptic”.

She said she did not want to do something “because it looks good” and “before we figured out how to do it”.

She pointed to speeches she had made in Parliament on the subject asking: “Lot’s of schoolchildren will be very happy, but where is the plan?”

She added: “Is net-zero a solution or is it a slogan… I am not sure we have properly thought that through.”

On immigration, she said “numbers matter but culture matters more”.

For several years, Conservative politicians have promised to get down the numbers coming into the country, but immigration has continued to rise, hitting record levels in 2022.

Badenoch said there should be a cap on numbers but it was also important to ensure those arriving “love British culture”.

Asked how the government should decide this, Badenoch said it was important to establish from which countries “successful migrants” were coming from.

“We should be getting to a point where we can say we’re happy to take more from countries A, B and C and for countries X, Y and Z, we’re going to have stricter rules.”

During the coronavirus pandemic, Badenoch was a Treasury minister. She said she would not apologise for spending “a lot” during Covid but added: “I think we just overran it to the point where it made inflation worse than it needed to be.”

She also said she thought the government “overdid it in terms of the length of lockdown”.

“There was a King Canute sort of situation. I thought that we were trying to do too much, that this was where government was overstretching itself and we weren’t trusting people enough.

“The biggest thing I hated was the fixed penalty notices.”

The notices were issued by the police to people who breached Covid rules, resulting in fines of between £200 and £10,000.

Both Boris Johnson and Rishi Sunak, the prime minister and chancellor during the pandemic, were issued with fines for breaching the regulations.

Badenoch said: “If Boris did not bring in those fixed penalty notices, he would not have had the Partygate scandal, certainly not to the extent that it was… he got caught in a trap that he had set for himself.”

She said Conservatives had “strayed away” from their principles of freedom.

Asked about her own leadership style, Badenoch said she aspired to be a “fun” leader and would try to bring some “humour” and “light-heartedness” to her approach.

“I think that we’ve been very gloomy. We’re not the gloomy party. We are actually quite an optimistic and fun party and I want to bring that out.”

Reflecting on her own background, she compared finding out that she was a British citizen to “finding out that you’d won the lottery”.

Badenoch explained that because she was born in Nigeria, a Commonwealth country, before a 1983 rule change, she qualified to be British – something she only found out when she was 14 years old.

She said there was a “very unpleasant sort of ethno-nationalist anti-Kemi wing” who called her an “anchor baby” – a term used in the United States to refer to people who ensure their children are born in the country in order to gain residency.

Badenoch was born in the UK because her mother had come to get medical care at a private hospital, but she said that is not why she qualifies as a British citizen.