AS Tory leadership contender Andrea Leadsom launched her bid to replace David Cameron, she was attacked by civil servants who accused the former Treasury minister of being a “disaster”.

It is highly irregular, if not completely unheard of, for civil servants to make an intervention in the internal election of a political party. But so worried are they about the prospect of Leadsom as prime minister, that two of those who worked closely under her at the Treasury have briefed the press.

Leadsom’s one-year stint from 2014-15 at the Treasury as City minister was “a disaster” said one official. “She was the worst minister we’ve ever had.”

“She found it difficult to understand issues or take decisions,” claimed another Treasury official. “She was monomaniacal, seeing the EU as the source of every problem. She alienated officials by continually complaining about poor drafting.”

Leadsom has come from nowhere to be a strong challenger for the top job. According to the current tally on the Conservative Home website, Leadsom has the support of 38 Tory MPs, compared to Michael Gove’s 26, Stephen Crabb’s 22, Liam Fox’s seven and Theresa May’s 110.

Although May is way out in front, MPs only whittle the candidates down from five to two; it is party members rather than MPs who make the final decision. And according to their most recent poll of party members, Conservative Home puts Leadsom out front by 38 per cent to May’s 37 per cent.

Cat Boyd: May, Leadsom, Eagle – a feminist revolution? No... feminists don’t make other women’s lives harder

Today is the first round of voting, and, by 6pm, the candidate liked the least by their colleagues will see their leadership ambitions dashed against the rocks of Tory backbench indifference.

Leadsom has attracted prominent Brexiteers including Iain Duncan Smith and Bill Cash, and in her launch speech promised to get the UK out of Europe quickly as “neither we, nor our European friends, need prolonged uncertainty.”

At a hustings for Tory MPs last night, Leadsom was asked to account for her closeness to Ukip and their millionaire banker Aaron Banks.

One senior cabinet minister said: “When you’re having to say that you’re not Ukip at a hustings to be leader of the conservative party you are in trouble, it was a car crash.”

However, Leadsom did win the backing of Boris Johnson, who last night told reporters he thought she would have the “zap, drive and determination” to be prime minister. Johnson’s bid to be leader of the party was reportedly torpedoed by Gove because the former Mayor of London failed to send Leadsom a letter confirming a place in his cabinet.

Liam Fox also launched his campaign yesterday, focussing on security and criticising rivals for treating the referendum and the contest like a “political parlour game”.

Fox, who was forced to resign in disgrace as defence secretary after allowing his friend access to top secret files said: “The winner of this contest on day one will be asked to set out the instructions for the use of our nuclear deterrent, they will receive a call from Mr Putin and be expected to drive our international policy against the threats of Islamism, including in the Middle East. This is not the equivalent of Britain’s Got Talent – it matters.”

Attacks on the leadership contenders are becoming increasingly more vitriolic.

In a newspaper article Ben Wallace, who was the joint chairman of Johnson’s aborted leadership campaign, claimed Michael Gove was a security risk who would leak state secrets because he has “an emotional need to gossip, particularly when drink is taken, as it all too often seemed to be”.