Allies of Theresa May have stepped up their attack on Andrea Leadsom, with one senior minister suggesting she could become the Tory equivalent of Jeremy Corbyn because of her lack of support in Parliament.
Employment minister Priti Patel, who campaigned for Brexit alongside Mrs Leadsom, suggested that the energy minister lacked the experience and broad appeal to win a general election.
Ms Patel, who is backing Mrs May's campaign, compared the Home Secretary to Margaret Thatcher and said her experience is "second to none".
Read more: Tory leadership race gets even uglier as Leadsom accused of "disgusting" dig at May
In an interview with the Sunday Telegraph she warned that Mrs Leadsom could find herself unable to govern due to the lack of support from MPs, or win an election victory by appealing to swing voters.
"You win elections by having that broad appeal," she said. "Look at Labour right now, and the narrow appeal they have. We have to represent society as it is today and be a true voice for modern Britain and a positive Britain."
Mrs May secured her place on the leadership ballot by securing 199 votes from MPs, with Mrs Leadsom winning the support of 84 colleagues.
Ms Patel warned a victory for Mrs Leadsom could mean that the process of leaving the European Union would be harder to deliver, even though the energy minister backed Brexit and Mrs May had supported a vote to Remain in the EU.
Read more: Marianne Taylor: The three women who will determine Europe's future
"We have to govern," Ms Patel said. "To govern we have got to be able to carry the support of Members of Parliament. That's incredibly important. I don't need to give a re-run of what's happening with Labour right now."
Asked if Mrs Leadsom could become a Conservative version of Mr Corbyn, Ms Patel said: "We could end up in that situation. And then it becomes very difficult to govern and deliver the programme for Leave."
She added: "Right now we need an individual with a great deal of experience. She doesn't have that just yet, not yet. She is in government - but Theresa's experience is second to none."
Ms Patel said Mrs May was "on a par" with former prime minister Mrs Thatcher, the first female occupant of Number 10.
"She is on a par, there's no doubt about that, in terms of her ability, professionalism, her work ethic, but also what she wants for Britain. She wants us, not just to Leave, but also she has got the interests of our country firmly in her heart and Margaret Thatcher was exactly the same."
Read more: Leadsom argued Scotland was 'heavily subsidised' by English
Former Tory leader Iain Duncan Smith dismissed the comparison between Mrs Leadom's position and that of Mr Corbyn when she secured second place in the MPs' vote on Thursday.
He told the Press Association: "Honestly, no comparisons with Corbyn. I have to tell you, this is a smart woman who has real intellectual capability, she is very easy, she speaks well, she's got real steel."
Ms Patel's comments came after Mrs Leadsom endured a barrage of criticism after appearing to suggest that being a mother gave her an advantage over her childless rival.
Mrs Leadsom said she was "disgusted" by the way her comments had been presented and insisted that she believed "everyone has an equal stake in our society", stressing that she did not want the issue of children to be a feature of the campaign.
In an interview with The Times, Mrs Leadsom said: "Genuinely I feel that being a mum means you have a very real stake in the future of our country, a tangible stake."
The Home Secretary has previously spoken about how she and husband Philip were affected by being unable to have children.
Business minister Anna Soubry said Mrs Leadsom's comments meant she was "not PM material" while Scottish Tory leader Ruth Davidson said there was a "gulf in class" between the two candidates and senior MP Sir Alan Duncan said the energy minister's remarks were "vile".
Armed forces minister Penny Mordaunt, a supporter of the energy minister's leadership bid, said The Times report was an attempt to "smear" Mrs Leadsom.
Read more: Boris Johnson backs Andrea Leadsom for Conservative leader
Senior Tory backbencher David Davis, a former leadership contender, said Mrs Leadsom lacked the experience to be prime minister.
"She is intelligent and charming and so on, but what the events of the last week have demonstrated is that she has come under a bit of pressure - because leadership contests, as I know to my cost, are somewhat pressurised.
"But they are nothing like as pressurised as being prime minister."
He told BBC One's Andrew Marr Show she was "too inexperienced for a really important job at the most important time in our history".
Mrs Leadsom's campaign chief Tim Loughton denied that she was attempting to take back the party from modernisers.
He told the BBC's Andrew Marr Show: "There's nothing traditional about Andrea in that respect. This is not about trying to take back control of the Conservative Party.
"This is a fresh candidate in Andrea Leadsom who has much more experience outside of politics than all of the other candidates put together."
Read more: Next Prime Minister to be a women as May and Leadsom make the final two
He also defended her interview with the Times, insisting her children are what "fires her up".
He said: "She made it absolutely clear in that interview all the way through that in no way was her passion for her family and her children to be taken in any way derogatory towards Theresa."
Asked why she said it, he added: "People are fired up and inspired by different things.
"In Andrea's case, I know because I'm godfather to her son, her children are the thing that really fires her up."
Former minister Baroness Warsi believes it was a "slip of the tongue' but raised concerns about Mrs Leadsom's judgment.
She told ITV's Peston on Sunday: "I think it was a naive comment, which of course is worrying because she does want to be prime minister and we need to know that she is on top of her brief and knows exactly what she's saying when she's in negotiations.
"But was it malicious and deliberate? I don't think it was."
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here