Torcuil Crichton and Michael Settle

FOR someone who is known as a straight talker, David Davis's resignation speech, delivered on the steps of the Commons because he was refused permission from the Speaker to address the chamber, displayed the hubris that typifies the man.

Mr Davis claimed it fell on him, on the 600th anniversary of the signing of the Magna Carta, to take a stand against "the slow strangulation of British freedoms".

Few doubt his sentiments or his ability to return to Westminster after pulling off a by-election "stunt" but will he come back as the vindicated champion of civil liberties or the outsider whose pride has punctured the united image of David Cameron's Tories?

The Conservative leader described the move as a "courageous personal decision", a Yes Minister phrase helpfully decoded by television commentators as meaning "completely bonkers".

Mr Cameron was told of Mr Davis's attempt to be the solo saviour of human rights in a late night telephone call on Wednesday when Gordon Brown's cobbled victory on 42 days had been concluded.

One suggestion is that there was an "angry row" between the two over the party's stance on counter-terrorism.

Mr Davis had attempted to box in Mr Cameron by announcing he would, if he became Home Secretary, repeal the 42-day law. The Tory leader was more wary, merely committing to a review of the evidence.

Hence an impetuous move that left Westminster, and the Tory Shadow Cabinet gasping. One senior Conservative said David Cameron had been "bounced" and is now tied in to the noble battle of Haltemprice and Howden.

Mr Cameron is said to be "privately furious" and, by effectively challenging his judgement in public, the prospect of Davis getting back into the Shadow Cabinet is negligible.

Only one party leader will thank David Davis - Gordon Brown. Just as the Tories were gaining momentum Mr Davis has granted the PM much needed breathing space.

The fall out from the 42-day vote - Mr Brown's repeated "no deal" denials in his morning press conference - threatened to swamp his premiership but the political theatre at St Stephen's Entrance at lunchtime diverted attention.

Although not practised in a long time, the skill of soundbite mockery is not lost by cabinet ministers. On their first test on a major issue - national security - the Conservatives have collapsed in disarray, claimed Home Secretary Jacqui Smith.

The LibDems have stood to one side in the Davis crusade which portrays them as defenders of civil liberties. It also buys them a ringside seat as promoters of the Tory fratricide they hope the return of a victorious David Davis will trigger.

Of course, like the DUP support of Labour, LibDems claimed there was "no deal" with the Tories The only people who need this by-election less than David Cameron are the voters of an East Yorkshire constituency that is to be used as a referendum on civil liberties stretching from the Magna Carta to the "monstrous law" on 42 days. Even Mr Davis admits it is all "very risky" to stand down and fight a by-election full of imponderables.

Last night Labour were still considering not running so the crusader may be left fighting a "quixotic" battle, as one colleague described it. A low turn out with no real opponents could make Mr Davis look pointless.

The vote on the Yorkshire seat is likely to take place on July 10 and if Mr Davis loses it makes for a bad summer for Mr Cameron. If he returns as a hero from what Labour call a "vanity exercise" he poses even more problems for the Conservative leader.