David Davis, once seen as the natural inheritor of the Conservative leadership, might just have gone for a long walk into the political wilderness by resigning as an MP.

Davis, 59, has a reputation as political loner, a maverick, but also something of a conspirator.

As a Tory whip he was a great friend of that parliamentary Machiavellian, the late Alan Clark, and David Cameron's front-bench team will be trying to figure out just what Mr Davis is up to.

But none should doubt Mr Davis's libertarian sentiments, they are genuinely held.

His passionate resignation speech, casting himself as a defender of ancient freedoms, was better than the wooden address to the Conservative Party conference in 2005 when he was left in the leadership starting blocks by an unscripted and comparatively unknown David Cameron.

In the play-off election Mr Davis was left in the dust but Mr Cameron appointed his rival as Shadow Home Secretary, a role in which he excelled right up to the 42 days vote.

Mr Davis has been in parliament since 1987, served as government whip and became Europe Minister in the Major government, though he was always anti-European.

His instincts are socially conservative but his libertarian credentials have always been worn on his sleeve.

Although a gut right-winger he finished a poor fourth in the fight for the party leadership in 2001.

The winner, Iain Duncan Smith, made him party chairman but, suspected of plotting and branded as "lazy", he was sacked.

He has credentials, though, that would make a Labour candidate weep with envy.

Born in 1948 to a single mother, he grew up on a tough London council estate and was adopted by a Jewish print worker with strong trade union links.

He went to grammar school in Tooting, became an insurance clerk, went to a redbrick university and worked in business for 17 years before being elected.

He also served in the Territorial Army SAS. The "hard-man" image has served him well in politics, reinforced by his physical appearance.

His nose has been broken three times - once in schoolboy rugby, then a swimming pool accident and finally, the story goes, in a fight on Clapham Common. He is married with three children.

He is an affable and approachable politician who has won friends well outside the usual Tory circles.

He was, famously, a friend of Tony Blair's press secretary, Alastair Campbell but last night in Westminster his judgment was being questioned by all sides.

"There always has been a streak of madness about him," quipped a senior Liberal Democrat.

He's well regarded in the constituency of Haltemprice and Howden. The place has a reputation as blunt as his own. Still, when 65% of the population support moves to lock up terror suspects for 42 days, his is a high-risk strategy.

But then, who dares wins.

The man who once said Scotland was not very attractive

Profile

A descendant of Roxburghshire cattle rustlers, the new Shadow Home Secretary Dominic Grieve once earned a footnote in Scottish politics.

For two forgotten years, 1999 to 2001, when constitutional attention shifted to Holyrood, he served as shadow Scottish Secretary, distinguishing himself only by saying that Scotland was "not a very attractive place" for migrants to come to.

One would expect an Oxford-educated barrister to be more circumspect, particularly one with a skill for public speaking.

Recognised as one of the Tory party's most intellectual MPs, he was groomed for politics from childhood. While a pupil at Westminster School in London, Mr Grieve would often pop across the road to parliament to watch his father, Conservative MP for Solihull, Sir Percy Grieve, in action. He has represented Beaconsfield, a well-heeled Home Counties constituency, since 1997.

He has had roles as Conservative spokesman for criminal justice and community cohesion and was made shadow Attorney General in 2003.

Foreshadowing his law and order remit, the 52-year-old MP once made headlines when he chased a vandal who was destroying a London bus stop in a bid to secure his arrest.

Mr Grieve said at the time that "unless people are encouraged to participate with a little bit of gentle law enforcement", crime could not be beaten.