Tory leadership contender Andrea Leadsom is under pressure from some of her own supporters to “clear the air” with Theresa May after suggesting that she would make a better prime minister than the home secretary because she had children.

Andrea Leadsom urged to sign 'clean campaign pledge' amid motherhood row Read more

Leadsom, who is battling with May for the votes of some 150,000 party members in the race to become Tory leader and PM, provoked a furious reaction after making the comments in an interview with the Times.

But while Leadsom insisted she had done nothing wrong and that she had been misrepresented, even MPs who have backed her campaign to date conceded privately that she had made a bad mistake and should apologise to May for giving the newspaper ammunition for such a story.

One said: “I am very depressed. There can be no way this is right. What I want is to bring the two together in some way to clear the air.”

Another Leadsom backer said she had been guilty of naivety at worst, not of a deliberate attempt to score political points and get ahead in the campaign. “Andrea needs to learn how to deal with the press and be in the spotlight. This is not necessarily fatal for her, but she has to learn pretty fast. Having said that, I do think there was an element of entrapment.”

In the interview, Leadsom appeared to suggest that she believed that having children was an advantage for a prime minister as it meant he or she had a stake in the future.

She told the Times, which has produced a recording of the full interview, that May “possibly” had nieces and nephews. “But,” she continued, “I have children who are going to have children who will be a part of what happens next.

“I am sure Theresa will be really sad she doesn’t have children, so I don’t want this to be, ‘Andrea has children, Theresa hasn’t’, because I think that would be really horrible.”

But she added: “Genuinely I feel that being a mum means you have a real stake in the future of our country, a tangible stake.”

May made it clear last week that she and her husband, Philip, had wanted to have children, but had been unable to do so.

She said the couple had been “affected” by not having a family, but added that “you accept the hand that life deals you”.

May’s supporters said in private that they were appalled by the remarks, and called on Leadsom to sign May’s five-point campaign pledge, which includes a commitment to keep the contest within the “acceptable limits of political debate”.

A spokesman for Leadsom refused to say if she had telephoned May to discuss the matter, or whether she had apologised for speaking in a way that could be misinterpreted. The interviewer, Rachel Sylvester, said that she was “baffled” by Leadsom’s response to a report that was based on remarks in a taped, on-the-record conversation. Leadsom’s initial response was to say in a tweet that was directed at Sylvester: “I’m so angry. I can’t believe this. How could you?”

Speaking at the Nato summit in Warsaw, foreign secretary Philip Hammond – a May supporter – called on Leadsom, the energy minister, to ensure that the final eight weeks of the contest were conducted in a more civilised manner. She should sign May’s campaign pledge, Hammond said. Tory members “do not want to witness a slanging match or see any backstabbing”.

He added: “What makes you qualified to be prime minister is having long experience and a clear understanding of the big issues facing this country and a proven track record of being robust in face of the many pressures that people at the front line of politics face all the time.

“That’s why I’m backing Theresa May to be next Tory leader and next PM.”

An audio recording of the interview and a written transcript that verified the story was released by the Times after Leadsom had demanded one.

Two senior Eurosceptic figures in the party, Norman Tebbit and Bill Cash, say in the Observer that they will continue to back Leadsom. Both of them want the next prime minister to be someone who had backed the Brexit camp during the referendum campaign.

The outgoing leader of Ukip, Nigel Farage, writing in a column for the Mail on Sunday, said that Leadsom had the “guts” to take on Brussels. He dismissed May as “cold” and lacking courage, and said of the home secretary: “If she actually believed in our county’s liberty – and remember there were suggestions she would be leading the out campaign for a few short hours back in February, then she should have done so.”