Incoming prime minister Theresa May is a tough, hard-working pragmatist who now has the task of uncoupling Britain from the European Union, and of uniting her country and her party.

May takes over on Wednesday as Britain's second female prime minister after fellow Conservative Margaret Thatcher, succeeding David Cameron after he resigned in the wake of the shock vote for Brexit on June 23.

The 59-year-old, who has been Cameron's interior minister for the past six years, had officially backed her boss's campaign to stay in the EU.

But she kept a low profile, emerging relatively unscathed after the vote and presenting herself as the leader who could unify a nation deeply split by the referendum.

She insists "Brexit means Brexit" but has promised to work for the best deal for Britain outside the bloc.

In an unguarded moment, senior Conservative Ken Clarke labelled her a "bloody difficult woman" -- a description that May has embraced.

"The next person to find that out will be Jean-Claude Juncker," she reportedly told MPs, referring to Brexit negotiations with the European Commission president.

- 'Nasty party' -

May became a Conservative lawmaker in 1997, holding the post of party chairman before entering the cabinet after the Conservatives won the 2010 general election.

Unusually for someone who has been in front line politics for so long, she has guarded her privacy closely.

May is a keen cricket fan and lists her hobbies as walking and cooking. In an interview for BBC radio, she selected the Abba song "Dancing Queen" as one of her favourites.

She is well known for her collection of leopard-print kitten heel shoes -- a contrast with her sober demeanour.

May is a regular at her local church in her London commuter constituency of Maidenhead, where residents describe her as approachable and hard-working.

"She's very popular because she's committed and dedicated, she will be for the country too," Maxine Lattimer, a 46-year-old housewife, told AFP.

In a rare personal interview marking her leadership bid, she described how she and her husband Philip had come to terms with not having children, saying that "you accept the hand that life deals you".

May's rival Andrea Leadsom prompted widespread criticism for suggesting that her lack of children made her less qualified to be a prime minister. Leadsom withdrew from the leadership race two days later.

May was born Theresa Brasier in the southern English seaside town of Eastbourne in 1956.

Her father Hubert was an pastor, one of several points which has drawn comparisons between her and German Chancellor Angela Merkel.

Her education -- at a series of little-known state and private schools -- has been contrasted with the elite Etonian background of Cameron and many of his inner circle.

Like Cameron, she attended Oxford University, where she met her husband, a banker. They were reportedly introduced by Benazir Bhutto, who later became Pakistani premier, and were married in 1980.

May worked in finance, including at the Bank of England, before being elected.

As party chairwoman in 2002, she made waves by suggesting the Tories were seen as "the nasty party" and needed to overhaul their image -- something Cameron has largely managed.

- 'Safe pair of hands' -

May's job for the past six years, home secretary, is viewed as one of the hardest jobs in government which has wrecked a string of other political careers.

Supporters say her achievements include deporting radical cleric Abu Qatada to Jordan -- where he was later freed after a decade of legal cases -- and standing up to the Police Federation, the powerful police officers union, to try and address a string of scandals.

In 2013, May revealed she has type 1 diabetes but insisted it would not affect her career, saying it was a question of "head down and getting on with it".

She is not part of any clique at Westminster, acknowledging that she does not drink in parliament's many bars or "gossip about people over lunch".

A source who has worked closely with her told AFP on condition of anonymity she has "always got up three hours before everybody else and knows five times more than anyone else in the room".

"Theresa is not going to do anything radical... she's incredibly risk-averse, a safe pair of hands," the source said.