Andrea Leadsom misspoke about motherhood because she is so passionate about children, says Iain Duncan Smith

Former cabinet minister Iain Duncan Smith has defended Tory leadership contender Andrea Leadsom who has been criticised for her comments on motherhood.

The former Work and Pensions Secretary said Ms Leadsom was “stiched up” in an interview with the Times where she seemed to suggest she would make a better leader than Theresa May because she had children.

Mr Duncan Smith said Ms Leadsom's passion for children, highlighting her charity work with troubled families, led her to “slip into” discussing parenthood and its effect on leadership.

He criticised various Tory MPs sniping at the junior Energy minister in a “Black Ops” operation to “denigrate her reputation”.

Mr Duncan Smith told Robert Peston on his ITV politics show:

“I’ve been around in politics long enough to see plenty of incredibly experienced cabinet ministers and Prime Ministers get stitched up in the course of an interview.

“I’ve talked to her, she’s actually mortified about that, really genuinely mortified.

After admitting Ms Leadsom was not manipulated into making the statements, Mr Duncan Smith said: “The point about it is that she is really really passionate about children in general and her children and this is therefore easy to let her slip into this process where she talks about this because it is a big issue for her.

“And really you know talking about your family shouldn’t be a crime in politics, you know the question really is, is it because you talk about your family, you’re juxtaposing it against somebody else, not at all.

Mr Duncan Smith has called on Ms Leadsom's critics to let cooler heads prevail in the leadership campaign, saying: “I have a simple comment to them, which is calm down for God’s sake. This is a leadership election and I think people come to regret some of the silliest things they say during a leadership election. I’ve seen it all before – the reality is that both of them are qualified.

“Look, if Andrea was so unqualified to be Prime Minister, and you know we’ve had a lot of sniping, a kind of real ‘Black Ops’ operation to denigrate her reputation.

“If she was so bad what in heaven’s sake would the Prime Minister be doing making her a serious Government minister?”

Theresa May has invited Ms Leadsom to also sign a clean campaign pledge to stay within “acceptable limits of political debate”.

Foreign Secretary Philip Hammond, who is backing the Home Secretary, said of Ms Leadsom while at the Warsaw Nato summit: “Most of my colleagues [fellow European foreign ministers] do not know Andrea Leadsom and have not heard of Andrea Leadsom.”

Andrea Leadsom said in the now-controversial interview: “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 genuinely I feel that being a mum means you have a very real stake in the future of our country, a tangible stake.

“She possibly has nieces, nephews, lots of people. But I have children who are going to have children who will directly be a part of what happens next.”

Ms Leadsom has already caused controversy by her recent comments on gay marriage where she insisted she supports same-sex relationships but felt Gay marriage hurts Christian intepretation of marriage.