Who is David Davis? The Brexit minister taking legal action against the Government – in an EU court

David Davis's appointment as Brexit Secretary will be a dream come true for the former Europe minister who delighted in the nickname of "Monsieur Non".

A long-standing Eurosceptic, his Cabinet posting ends a spell in the political wilderness after he walked out of David Cameron's front bench on a point of principle.

Theresa May's decision to put him in her top team comes despite Mr Davis pursuing legal action in the European courts against surveillance laws she introduced.

The Tory MP joined forces with Labour deputy leader Tom Watson to jointly challenge the legality of the Government's Data Retention and Investigatory Powers Act 2014.

As Secretary of State for Exiting the European Union he will be keen to play hardball in the negotiations to take Britain out of the bloc.

Mr Davis gained a fearsome reputation after taking a series of ministerial scalps in the role of Shadow Home Secretary.

Among those he claims as his victims are former home secretaries David Blunkett and Charles Clarke and ex-home office minister Beverley Hughes.

He was regarded by many as the likely next Tory leader after Michael Howard announced he was to resign, but after a weak campaign - in his second tilt at the leadership - he was soundly beaten.

His rival, David Cameron, had caught the mood with his careful presentation and youthful optimism.

On the 42-day detention issue, Mr Davis had to persuade Mr Cameron and George Osborne that the party should be firmly on the side of civil liberties.

In June 2008 he shocked Westminster by announcing that he was resigning as an MP to "take a stand" against the terror detention plan, sparking a by-election that saw him hold his Haltemprice and Howden seat.

A libertarian who was never afraid to speak his mind, even if his opinions fell outside the party line, he worked closely with former Liberty director Shami Chakrabarti.

His friendship with former Downing Street spin chief Alastair Campbell raised Conservative eyebrows.

Mr Davis once revealed that he offered to buy Mr Campbell's old newspaper the Daily Mirror so the former journalist could edit it.

He put their unlikely friendship down to his liking for "strong mavericks" and there is something of that description in him.

His upbringing was far from that of a typical Tory MP. Brought up on a south London council estate by his single mother, he shone at grammar school and got an Army scholarship to Warwick University, hence his membership of the Territorial SAS.

As a part-time member of the SAS, he has broken his nose no fewer than five times.

He also studied at Harvard before starting a successful business career at Tate and Lyle. His background, supporters argued during his Tory leadership campaign in 2005, made him ideal to win back the working-class voters who had deserted his party for new Labour.

Despite Eurosceptic views, he acted as a whip for John Major during the bruising battle to ratify the Maastricht Treaty.

In the 2001 leadership contest Mr Davis cut his losses and quit after twice finishing way down the pack in early ballots of Tory MPs, throwing his support behind Iain Duncan Smith.

The contest successfully raised his profile and Mr Duncan Smith appointed him party chairman.