The row over Andrea Leadsom's comments about politicians and parenthood escalated as her allies accused Conservatives MPs of using underhand techniques against her.

Former leader Iain Duncan Smith claimed members of his own party were plotting "black ops" against the Tory leadership candidate.

Mrs Leadsom faced intense criticism over the weekend after she said in an interview with The Times: "Genuinely I feel that being a mum means you have a very real stake in the future of our country, a tangible stake."

Of her rival Theresa May, who has spoken of how she was affected by being unable to have children, she said that the Home Secretary "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".

Yesterday, some Tory MPs suggested that they could even leave the party in protest at a Prime Minister Leadsom.

A member of Mrs May's camp warned that the energy minister could become the equivalent of Labour's Jeremy Corbyn, a leader with little support among his own MPs.

Mrs May will try to move on from the row with a campaign speech in Birmingham today (MON).

She attempt to place the Conservatives squarely in the political middle ground , as the party of the workers.

She will outline a number of pledges, including to put staff on the boards of major firms.

And she will tackle so-called 'fat cat' pay, promising to make the decisions of shareholders binding.

Her supporters insist that elections are won from the centre ground

and paint Mrs Leadsom as an inexperienced extremist.

But Mr Duncan Smith claimed that she was facing a "black-ops" campaign

by Tory MPs keen to "denigrate her reputation".

Mr Duncan Smith appealed to Conservative MPs to "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," he

said. "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?"

The Employment minister Priti Patel, who campaigned with Mrs Leadsom

for a Brexit vote, suggested that she would lose a

general election.

Ms Patel, who is backing Mrs May's campaign, said: "You win elections

by having that broad appeal.

"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 was far out in front of Mrs Leadsom in last week's vote among

Conservative MPs.

But the choice of the UK's next Prime Minister lies with 150,000

Conservative party members.

While Mrs May is still the bookies choice, Mrs Leadsom could appeal to an electorate which overwhelmingly backed a Brexit.

After the interview was published Mrs Leadsom said she was "disgusted"

by the way her comments had been presented.

In response the newspaper release the full transcript and audio.

Mrs Leadsom was forced to later insist that she believed that

"everyone has an equal stake in our society".

Meanwhile, Mrs May's campaign chief, Brexit-backer Chris Grayling, had to deny that there would be another EU vote if the Home Secretary won.

He also said that he expected EU citizens would be able to remain in the UK after Brexit.

Mrs May has refused to make that guarantee unless she receives a

similar commitment from the other 27 member states about

the future rights of Britons overseas.

Mrs Leadsom has pledged that all EU nationals will be allowed to stay

in the country.

But her opponent accused her of naivety saying that the promise would also apply to foreign criminals.