Rory Stewart enjoys walking with a calm and purposeful air into danger. While other ministers keep their heads down, he has been out and about on the airwaves, defending Theresa May’s Brexit deal as one to which all moderate, sensible people should assent.

And while other contenders for the Conservative leadership keep up the threadbare pretence they are not competing for it, he told Katy Balls of The Spectator, and has repeated since, that he would like to be Prime Minister, and reckons he has what it takes.

His promotion a week ago to the Cabinet as International Development Secretary suddenly makes him look a more plausible candidate. He has fewer enemies than his longer established rivals, which in Tory leadership contests can be a decisive factor, as Michael Heseltine will tell you.

But few people at this level are entirely without enemies, and his career so far as a departmental minister, which began four years ago, will now come under scrutiny, in a way that was not possible when this exotic figure, who in his life before politics had a number of unusual adventures, was first profiled for ConHome in 2015.

Andrew Mitchell, who served as DFID Secretary under David Cameron, told ConHome:

“I think he will be a very good DFID Secretary. He already has significant development experience outside the political system as well as within it, and will bring some new and updated ideas to the way Britain makes its contribution to solving some of the big international problems that beset us.”

But others who observed Stewart when he was Minister of State at DFID from 2016-18 report that some of the senior officials there “literally hated him”.

One former colleague predicted that his appointment as DFID Secretary will be “a disaster” and “could well lead to the death of thousands of the world’s poorest people”.

Stewart is accused of “not listening to advice”, “saying things that weren’t realistic”, “going with ideas he’s just made up on the back of a napkin”, and horrifying the civil servants who were sitting beside him as he spoke.

This capacity for challenging the departmental orthodoxy, and refusing to accept what his officials say, could be a great strength or a mortal weakness. He is committed to thinking things out for himself, and tenacious in defence of what he thinks are the right ideas.

Almost everyone agrees that Stewart is tremendously articulate and engaging, and has “very good big ideas”. Some add that he is not at home in large organisations, though they often remark in the same breath that he has excellent manners.

In The Places in Between, his acclaimed account of the walk he made across Afghanistan in 2002, Stewart is scathing about the post-conflict experts who set out to solve that country’s problems without any knowledge of the people they purport to be rescuing.

In an impassioned outburst on pages 293-4, consigned to a footnote because it is polemical rather than descriptive, he writes:

“Critics have accused this new breed of administrators of neo-colonialism. But in fact their approach is not that of a 19th-century colonial officer. Colonial administrations may have been racist and exploitative but they did at least work seriously at the business of understanding the people they were governing. They recruited people prepared to spend their entire careers in dangerous provinces of a single nation…

“Post-conflict experts have got the prestige without the effort or stigma of imperialism. Their implicit denial of the difference between cultures is the new mass brand of international intervention. Their policy fails but no one notices. There are no credible monitoring bodies and there is no one to take formal responsibility. Individual officers are never in any one place and rarely in any one organisation long enough to be adequately assessed. The colonial enterprise could be judged by the security or revenue it delivered, but neo-colonialists have no such performance criteria. In fact their very uselessness benefits them. By avoiding any serious action or judgment they, unlike their colonial predecessors, are able to escape accusations of racism, exploitation and oppression.”

Many readers will cheer these sentiments, and will reckon they help to explain why international intervention so often fails even in its own terms.

But oddly enough, Stewart is himself open to the charge of not staying put long enough to be adequately assessed.

From January 2018 to May 2019 he served as Minister of State for Prisons. In August 2018 a BBC interviewer asked him, in an incredulous tone, if he would resign, if in a year’s time he had failed to reduce the level of drugs and violence in ten prisons which had just been targetted by the Government, with a million pounds to be spent in each of them on new measures.

Stewart replied, after a fleeting pause: “Yep, I will quit…I will resign if I don’t succeed.”

No one can just now know whether in August 2019 he would have had to resign as Prisons Minister, for he no longer occupies that post, and can no longer urge the vigorous implementation of the measures he set in train.

A prison reformer told ConHome it is impossible to know what will happen in the ten prisons, but remarked that turning round a prison usually takes longer than a year.

Mark Fairhurst, Chairman of the Prison Officers’ Association, said:

“Rory Stewart has been given a get out of jail free card.

“The pledges [Stewart] made and the way he engaged with us and listened to us were positive, but the question is what happens now?

“This is the problem. You forge a good working relationship with these ministers, and you start to make progress, because certainly the things he’s implemented are things that we’ve been calling for years. But then all of a sudden, just as you’re moving forward, they get replaced or promoted.”

Stewart himself said in the Commons on 23rd April that “the figures are looking reasonably positive”, and indicated that he hoped to survive in his post after August. He has not, incidentally, been replaced yet. Whoever takes the job will be asked whether he or she will promise to resign.

Jonathan Aitken, who knows the prison system from the inside and has served for the last year as chaplain at Pentonville Prison, reckons that “as a prison minister, Stewart has been a considerable success, but part of that is just sheer luck”, because the spending needed to increase the number of prison officers from dangerously low levels had already been approved, and staffing levels have dramatically improved over the last year, though there has not yet been a corresponding drop in violence.

Aitken said that at Leeds, one of the ten prisons targetted by Stewart, the extra million pounds is having a good effect, for example by putting in better windows to replace those through which drugs were being smuggled, and installing an X-ray body scanner to search for drugs.

In Aitken’s view, “As a dark horse bet [in the leadership race] Stewart is quite interesting. He’s cut from a different cloth. He’s got a most unusual mind. They’re all going to be looking for someone who can unite the party a bit.”

Although his pledge to resign will not now be put to the test, it did attract a lot of attention to what he was trying to do. His approach is different to that of the standard career politician who seeks to avoid anything which might be regarded as new or alarming.

More conventional spirits doubt it can be good politics for Stewart to advertise his leadership aspirations so openly.

But a considerable number of people at Westminster said yesterday that although this was “naive”, it was also “charming”. There is something refreshing about a man who ignores the usual hypocrisies.

Not since Sir Alec Douglas-Home in 1963 has an expert on foreign affairs, who knows next to nothing about economics, become Conservative leader. The precedent is not encouraging for Stewart, who seems more cut out to become Foreign Secretary than Prime Minister.

Stewart admits that having voted Remain in the EU Referendum is a drawback for him, and this aspect of him renders him intolerable to those who think the next leader simply must be a Leaver. He offers himself as a centrist who would implement Brexit while striving to maintain close economic ties with the EU, and to retain the support of the four million Remain voters who also voted Conservative:

“If the Conservative Party make the mistake of trying to out-do Nigel Farage, which I am sure we won’t, but it is something that a few of my colleagues are talking about, then we would lose those four million Remain votes.

“We’d lose young people, we’d lose Scotland, we’d lose London and we’d lose a lot of the most energetic parts of this country.

“We’ve got to be a broad party…”

Could Stewart speak, for example, to Leave voters in the Midlands? The only answer to that question at the moment is that nobody knows for sure, but it seems a bit unlikely.

Stewart loves traditional institutions such as the monarchy (he acted as tutor to Princes William and Harry) and the armed forces, but also displays a boldness and an independence of mind which were perhaps more often found in the Victorian period than they are now.

When Margaret Thatcher fell, the relatively obscure John Major swept to victory as the stop Heseltine candidate.

When Theresa May falls, it is not yet clear (at least to the present writer) who will be the Stop Boris Johnson candidate. Timing can be almost everything in such contests, and Stewart has reached the Cabinet just as the race is starting.