THERESA May, dubbed a “bloody difficult woman” by former chancellor Ken Clarke, looks certain to top the Tory leadership poll tonight, gathering support from more than half of the 330 Conservative MPs.

The colourful description from Mr Clarke led Scottish Conservative leader Ruth Davidson to tweet: “If I was Nick Timothy[the home secretary’s former chief of staff and now part of “Team Theresa”], I'd get ordering some ‘Cometh the bloody difficult hour, cometh the bloody difficult woman’ merchandise immediately.”

The Nottingham MP made his views known about Mrs May in unguarded off-air comments with fellow Tory veteran Sir Malcolm Rifkind, which were caught on camera and broadcast by Sky News.

"Theresa is a bloody difficult woman but you and I worked with Margaret Thatcher," declared the former cabinet minister, who clashed with Mrs May while he was in office but who stressed that he got on alright with her "and she is good".

But he added that she had been at the Home Office "far too long" and "doesn't know much about foreign affairs".

Sir Malcolm was equally indiscreet but about fellow Scot Michael Gove.

He told Mr Clarke in the off-air chat: "I don't mind who wins as long as Gove comes third. As long as Gove doesn't come in the final two I don't mind what happens."

Later, when questioned about his remarks, the former foreign secretary was unapologetic, saying: “My comments speak for themselves and they appear to be shared by quite a high proportion of the human race."

Mr Clarke was also critical of the Justice Secretary, claiming the party membership would not vote for him.

He said: "I remember being in a discussion about something to do with somewhere like Syria or Iraq and he was so wild that I remember exchanging looks with Liam Fox, who’s more right-wing than me. We were exchanging views and Liam was raising his eyebrows.

“With Michael as prime minister we'd go to war with at least three countries at once," he added.

The former chancellor, who suggested he was likely to support Mrs May, commented on Andrea Leadsom’s candidacy, saying: “She is not one of the tiny band of lunatics who think we can have a sort of glorious economic future outside the single market. So long as she understands that she's not to deliver on some of the extremely stupid things she's been saying."

Mr Clarke, 78, also commented on the previous prospect of Boris Johnson entering No 10. Saying Mr Gove had done the party a favour by getting rid of the former London mayor, he said: “The idea of Boris as prime minister is ridiculous.”

He added that neither Ms Leadsom nor Mr Johnson were in favour of leaving the EU, suggesting the energy minister had had a “Pauline conversion”.

Business minister George Freeman, who's backing Mrs May for the leadership, asked about Mr Clarke's description of her as "a bloody difficult woman," replied: "Ken's earned the right to have his own opinions. I have to say that's not my experience of Theresa, and nor is it the experience of those who've worked with her, who are incredibly loyal and[are] supporting her, including senior cabinet ministers, who've seen her operate at the very highest level in government for over six years."

Asked whether David Cameron had found Mrs May "difficult" to work with, the Prime Minister's spokeswoman said: "He has found she has done a very good job as Home Secretary and they have worked very closely together on a whole range of issues."

When asked if this amounted to an endorsement of the Home Secretary as his successor, the spokeswoman replied: "It reflects the working relationship between Prime Minister and Home Secretary. It's not that different to how he works with other cabinet ministers."

Later, Sir Malcolm was asked about the broadcast by Sky News of the off-air remarks and said: “It was a bit naughty of them."

Meantime, Mrs May, who backed the Leave camp, has come under fire for her position on the status of EU nationals. At first, she seemed to suggest that this would be something to be negotiated as part of the Brexit talks but then at a Tory hustings made clear she “hoped and expected” they would stay.

But rival Scots-born Stephen Crabb said EU nationals living in the UK must not be forced into a post-Brexit "Checkpoint Charlie" situation.

He insisted that they should be given guarantees now rather than waiting for Brexit negotiations involving the status of the 1.2 million Britons living in other EU countries.

"The idea that we will be at some kind of Checkpoint Charlie scenario where we are arguing over trading people living in each other's countries; that is not going to happen.

"There is a danger here that we slip into a mindset of regarding the people who lead countries across the English Channel in Europe as our enemies - they are not," he added.

Outgoing Ukip leader Nigel Farage criticised Mrs May's stance on EU nationals in Britain, saying: "I am disgusted at the way May has been speaking. The EU nationals living in the UK came here legally and they have protected rights."

Labour’s Keith Vaz, who chairs the Commons home affairs committee, has written to Mrs May and Mr Cameron setting out his concerns about the Home Secretary's stance.

He said: "We believe European Union citizens who have acquired the right to live and work in the UK should not be used as a negotiating tool in any discussions between the Government and the EU over the terms of our exit.

"Fears over repatriation of these settled citizens is causing uncertainty and worry across the country, particularly following a number of racially motivated incidents which Commissioner Bernard Hogan-Howe has confirmed to have risen after the referendum."

Outside committee room 7, where the vote was taking place, the leadership candidates posed for photographs.

The candidate with the fewest votes, which at present looks like Scot Liam Fox, the former defence secretary, will be eliminated, with further rounds of voting on Thursday and next Tuesday until a final pair are left standing.

The choice between the two remaining candidates will be made by Tory members, with around 150,000 of them expected to decide on the identity of the new leader - who will also take the keys to Number 10 - ahead of a declaration on September 9.

Asked how he voted as he left committee room 7, Mr Gove joked: "It was a tough choice. I voted for a Scotsman."