Oaten: A tough liberal from the right of the party who knows the dangers of a Tory revival

No one expected Mark Oaten to win Winchester for the Liberal Democrats in 1997. But the former lobbyist confounded the pundits to wrest the Hampshire constituency from the Tories by a margin of two votes.

Eight years later he is about to make another audacious bid for a post that just months ago seemed out of his grasp.

His supporters are preparing to make heavy play of his espousal of "tough liberalism", mixing the party's traditional concern for civil liberties with recognition of the rights of crime victims. They will also point to his recent performance in debates on the Government's anti-terrorist legislation during which he broke the post-July 7 cross-party consensus by warning Ministers they could not expect a "blank cheque" for their proposals.

As Charles Kennedy battled to save his job before Christmas, Mr Oaten made several public protestations of loyalty to his leader and offered to run his re-election campaign. In return he will be hoping for Mr Kennedy's endorsement, boosting his hopes of winning support from disgruntled activists.

His critics allege his loyalty was skin deep and indeed Mr Oaten let slip his leadership ambitions last month when he sent an e-mail to party members outlining his achievements in his frontbench role.

The episode was grist to the mill of the parliamentary enemies he has accumulated during his rapid rise through the party's ranks.

He served in the foreign affairs and defence teams before Mr Kennedy gave him a roving brief as chair of the parliamentary party and cabinet office spokesman. During that time the ex-SDP councillor carved out a niche in the party's "Orange Book" faction of economic liberals and established himself as an articulate and persuasive television performer.

Mr Kennedy rewarded him with the home affairs portfolio in 2003, when he set about ridding the party of its enduring "soft on criminals" image.

Although he has now turned his former true-blue constituency into a safe Liberal Democrat seat, Mr Oaten is eloquent on the subject of not allowing his party to underestimate the threat from the Conservatives.

At 41 and married with two daughters, he would hope to project a youthful appeal to match David Cameron and counter Gordon Brown, the likely Labour leader at the election.

One of his lieutenants, Lembit Opik, the party's Welsh and Northern Ireland spokesman, said last night: "He is a natural leader of a party which is serious about getting into power."

Whether enough of the party's rank-and-file members know him well enough to hand him in the crown is doubtful, but whatever happens in March, Mr Oaten has finally established himself among the Liberal Democrats' big beasts.