No one messes with her: The Thatcherite steel that makes Theresa May favourite to win Tory leadership battle

How ironic, you may think, that talk of Tory leadership hopeful Theresa May in recent years has so often been prefaced by observations about her shoes. The fact is that the UK's longest-serving Home Secretary for more than a century, one of only two women - Margaret Thatcher theother - to hold one of the four great offices of state, is a surprisingly un-showy figure.

As any of her political colleagues will tell you, she never uses the kind of mild flirting that was sometimes employed by Margaret Thatcher in the presence of her more dashing ministers.

Those leopard-print kitten heels Mrs May favours aside, she is a politician who adheres to a muted style, and who has long been curiously underrated. Yet she has always been a deep thinker and a detailed planner. Just the kind of determined, organised figure - her supporters are now saying - to lead Brexit negotiations with Europe. This, even though she voted "on balance" for Remain.

Some serious thought undoubtedly went into her decision to vote to stay in Europe, just as it did 14 years ago when she chose to wear frivolous shoes while delivering a ferocious, headmistressy lesson about the Tories being seen as "the nasty party".

Today, at 59, Theresa May is the bookies' favourite to move into No 10.

A steely, apparently unflappable determination has taken her to this point - no mean feat for a woman diagnosed four years ago with Type 1 diabetes, who has to inject herself with insulin twice a day. Typically, she dismisses the issue as "a case of just getting on with it".

Some colleagues think the diagnosis has made her even tougher, giving her the inner core of steel that enabled her to face up to a pugnacious Police Federation conference year after year and warn them that she proposed to break their power and put an end to corruption allegations that risked destroying the very foundations of our policing.

This is also the Home Secretary - as she reminded us in her declaration speech yesterday - who succeeded in deporting the radical hate preachers Abu Qatada, whom previous Home Secretaries had failed to deport for 12 years, and hook-handed Abu Hamza.

The man May is going up against, Michael Gove, who eneded the leadership ambitions of former favourite Boris Johnson. Photo / AP

She did this while remaining a strong advocate of civil liberties, scrapping Labour's plans for compulsory ID cards soon after taking office in 2010, and easing the tensions between the police and the black and ethnic communities by revising the stop and search rules.

She also stood up to America's demands to get their hands on Gary McKinnon, refusing to extradite the young Briton who hacked into the Pentagon's computers because he suffers from Asperger's syndrome.

Even with that record, she is deceptively tough - tough enough to wring an apology out of Michael Gove. Two years ago Gove, now a rival for No 10, briefed The Times newspaper - as an anonymous source - that the Home Office was failing to "drain the swamp" of extremists, after it had emerged there was a "Trojan Horse" plot to Islamicise secular state schools in Birmingham.

In the course of the spat, Mrs May's special adviser Fiona Cunningham briefed against Gove and later resigned, while Gove was forced to write a formal letter of apology to the Prime Minister about his indiscretion.

The clash between the pair has done nothing to change Mrs May's working style, which is said to be "very closed, very controlling and very untrusting" - especially, it must be said, of male, public school-educated rivals.

Others in government have been irritated by what they perceive as her being over-cautious. At the same time, she is respected for fiercely fighting her corner. In short, I am told, "no one messes" with her.

In pursuing her career with such single-mindedness, she draws strength from her long and settled 36-year marriage to husband Philip, with whom she lives in Sonning, Berkshire.

The fact that the couple, who met at Oxford, have no children is a matter of sadness that she has never talked about publicly. Friends see this as part of the reason she immerses herself so very deeply in her work. She is often trawling through her ministerial red boxes often until two in the morning, or, for example, firing off emails on government matters on Christmas Eve.

Being without children is something she has in common with Germany's Angela Merkel, whom she admires for "getting things done" and who, like her, is also the daughter of a clergyman.

The vicar's daughter

It was largely through her father's work that Theresa decided, aged 12, that she wanted to be a politician.
Around the Oxfordshire countryside the Rev Hubert Brasier was a popular figure in the community. He and his wife Zaidee (so called because it was the name of Abraham's wife in the Old Testament) would talk about current local affairs over meals with their only child.

"You didn't think about yourself - the emphasis was on others," Mrs May has said. Becoming a politician was, says a friend, "a calling, a vocation, not seen as work". She remains a regular churchgoer, and was photographed leaving Mass last Sunday in smart jeans and a fitted jacket.

At 13, she won a scholarship to the local grammar school, Holton Park Girls, in Wheatley. She was there barely a year when it was turned into a comprehensive, linking up with a local boys' school.

"It was certainly an interesting time," says Kevin Heritage, the school archivist, ruefully. But Theresa seems to have sailed through the disruption without fuss, and at 18 she was off to St Hugh's College, Oxford, to read geography, a unusual subject for a budding politician.

No one spotted any star potential in the fairly quiet blonde girl, but she was a good speaker at the Union and an active member of another student debating group, the Edmund Burke Society, which in her last year she chaired, presiding over proceedings with a meat tenderiser as a gavel.

In fact it was her boyfriend and future husband - two years her junior - who attracted attention as a potential rising political star. Philip May was the toast of the debating chamber, a friend of Benazir Bhutto, the future Prime Minister of Pakistan who was to be assassinated in 2007.

It was Benazir who introduced Philip to Theresa at a Conservative association disco - he the centre of much attention, she the barely-noticed ex-grammar schoolgirl and vicar's daughter.

How ironic now if she follows Margaret Thatcher, whom she much admires, into No 10, and Philip assumes the Denis Thatcher role for which he seems now eminently suited. For his has become a quiet, background existence, supporting his wife throughout her escalating career as he, like Denis, follows a financial career, as an adviser to wealthy clients with a firm called Capital International. Though Denis's game was rugby, Philip's is cricket - a love he shares with Theresa. (Her idol is Geoffrey Boycott, the brilliant, but perhaps most self-regarding England batsman of all time. She admires his sheer skill and determination.)
Theresa and Philip married in 1980, soon after he graduated, though before coming down he persuaded her to return for one last Edmund Burke society debate. She spoke against the motion "That sex is good ... but success is better". No one recalls, or cares, who won.

Resolute toughness

By now Theresa was working as an analyst for the Bank of England. But already she was taking a first step in politics, becoming a councillor in Merton, South-West London, with responsibility for local schools.

She had a family link to the Wimbledon area - her paternal grandfather Tom Brasier, a World War I regular soldier decorated as a Sergeant Major with the Royal Green Jackets, was born there.

The woman Tom Brasier married, Theresa's grandmother Violet, had worked in service in a large house in Reading as a nursery nurse. (Intriguingly, her other, maternal, grandmother was also in service below stairs, a parlour maid at a house in Notting Hill.)

As Philip made his way in the City, Theresa's political ambitions took her to two losing seats, and then she landed the plum constituency of Maidenhead, not far from where she spent her childhood.

In the meantime, in 1981, her father was killed in a car crash. Theresa's mother, already in a wheelchair with multiple sclerosis, died a year later.

Mrs May entered Parliament at the time of the New Labour landslide of 1997, and two years later became the first of the new intake to be appointed to the shadow cabinet, as education spokesman and then Shadow Education Secretary under William Hague.

Her family have no doubt she has inherited the resolute toughness of her two below-stairs grannies, but that was not how it looked in her early days in Westminster. The gag going around went like this: "Theresa May - or she may not."

Behind the mockery was a belief that she was indecisive. The reality seems now to be that she was very exacting in extracting every last detail from an issue before making a decision.

As one MP who worked with her recalls: "She would examine the pros and cons of an issue until you wanted to scream."

She still prefers to comb through issues herself, with the help of her close advisers, often into the early hours. One close figure says she is a micromanager, "very wary" about other people trying to impose their views on her, "a bit of a loner who likes being in control of her own patch". These are not necessarily ideal qualities for a prime minister, for whom sensible delegation is a prerequisite if they are not to drown in paperwork.

Indeed, one senior figure, former security minister Lady (Pauline) Neville-Jones, left the Home Office after barely a year declaring she couldn't stand working with Mrs May because she was simply unable to delegate.