Don't underestimate Andrea Leadsom – she's far more popular than you think

The Conservative Party leadership decison will be made by the party's 125,000 members. They have form in choosing a right-wing, Eurosceptic, traditionalist Tory over a pro-EU rival

Conservative leadership contender Andrea Leadsom gives a speech on the economy at Millbank Tower (PA)

Only 20 months after she became an MP in 2010, I interviewed Andrea Leadsom. She was not backwards in coming forwards, and already had an experienced press officer on board. She was delighted with the resulting headline in The Independent: “New ‘Iron Lady’ orders Cameron to win back powers from Brussels; Incoming head of Tory Eurosceptics has drawn up ‘shopping list’ for PM.” Even as a new MP, she was very keen to be seen as the new Margaret Thatcher.

Just four years later, remarkably, Leadsom is on the brink of becoming our second woman prime minister. In the interview, she insisted her “Fresh Start” project, which reviewed every aspect of the UK-EU relationship, was not part of a campaign to get Britain out. She described her group as pragmatic Eurosceptics, saying the vast majority of Conservative MPs wanted to remain in the EU.

Times have changed. Today Leadsom says she has been on a “journey” since then. She believes that David Cameron’s renegotiation of our EU membership terms was thin gruel – and is right, since he only mentioned it when asked about it during the referendum campaign.

Although Theresa May starts as the favourite in the run-off to choose Cameron’s successor, only a fool would bet against Leadsom. Why? Because the decision will be made by the Tory party’s 125,000 members. They have form in choosing a right-wing, Eurosceptic, traditionalist Tory over a modernising, more socially liberal and more pro-EU rival: they preferred Iain Duncan Smith to Kenneth Clarke in 2001.

Today’s members should recall that Duncan Smith was so obviously unsuited to the job that he was ousted two years later by Tory MPs in a coup organised by the party’s whips. And that several of the MPs who backed Duncan Smith – and the man himself – are supporting Leadsom.

Perhaps the Tory members will take account of Labour’s current civil war, in which the leader does not enjoy the confidence of 80 per cent of his MPs, but is backed by the party’s members. In this week’s votes, May won the backing of six in 10 Tory MPs, and Leadsom only a quarter.

May’s trump card is that the Tories are choosing a prime minister in the middle of the country’s biggest crisis since the Second World War. If the party were in opposition, I think Leadsom’s “Fresh Start” pitch would prevail. It still might, given that a majority of Tory members voted for Brexit.

But there are several reasons why they should think carefully before handing the Downing Street keys to Leadsom, a middle-ranking minister not yet in the Cabinet. It is true that neither Tony Blair nor Cameron had been a minister when they moved into Number 10. But they had both been leader of the opposition, a job, for good reason, often described as the toughest in politics.

Talking yourself up as the new Maggie Thatcher is hardly a crime in a party that still reveres her. But the doubts about whether Leadsom overegged her career in banking should be taken seriously by Tory members in an age when the public expect more transparency from their political leaders. There was no need for Leadsom to embellish her CV, as former colleagues in the City claim (and which she denies). She already had a perfectly respectable track record, and enough experience to justify her label as “real world” candidate.

Similarly, her refusal to publish her tax return until she made it into the contest’s final round – unlike the other candidates – should raise eyebrows among Tory members. The public expect those in the spotlight to undergo more scrutiny than they once did.

On my travels this week I have been struck by the doubts about Leadsom in Whitehall. It appears that civil servants in her current department, Energy and Climate Change, and her previous berth at Treasury, do not see her as prime ministerial material – for now, at least. As one senior figure told me: “As Treasury Economic Secretary [responsible for the City of London], she ignored large parts of her brief and pursued her own hobby horses. That might be all right for a junior minister; it is not all right for a prime minister who has to be on top of everything.”

Other Whitehall officials wonder what the untested Leadsom would do in a crisis, pointing out that May is well versed on the terrorist threat as Home Secretary and has chaired meetings of the Cobra emergency committee. “The question is: who would you want to be in charge if Putin invaded Estonia?” said one Whitehall source.

May is viewed by civil servants as a workaholic, a control freak who wants to know the fine print of every Home Office decision, and not the natural delegator that a PM should be. She is regarded as a hard but fair taskmaster. Crucially, she enjoys their respect. “The new captain will need the support of the team around her; otherwise we might hit the rocks,” said one official.

Now such whingeing will be cited by Leadsom’s allies as evidence that Whitehall needs precisely the breath of fresh air that she would bring. Some colleagues in the Vote Leave campaign would like her to put a rocket under the civil service to sweep away the Yes, Minister culture and prevent Sir Humphrey diluting or sabotaging the public’s decision in the referendum.

Tory members may like Leadsom’s right-wing instincts but they could cause big political problems for the party. In 2012, Leadsom proposed the scrapping of all regulations for businesses with three workers or fewer. She said: “I envisage there being absolutely no regulation whatsoever – no minimum wage, no maternity or paternity rights, no unfair dismissal rights, no pension rights – for the smallest companies that are trying to get off the ground, in order to give them a chance.”

During the referendum campaign, Leadsom promised that all EU legislation on workers’ rights would “remain in place if we vote to leave”, at least until the next general election, and dismissed “blood-curdling warnings” to the contrary. But which Leadsom would enter Number 10: the original or the recent one?

Tory members face a daunting choice. This election is about much more than a battle between two women, and between the traditional and modernising wings of the party. It is about the future of the UK. The members might think it is the right time for the country to be led by a Leaver. But they should consider whether, to paraphrase Gordon Brown’s 2008 put-down of David Miliband, it is the right time to be led by a novice.