By Nyta Mann BBC News Online political correspondent

Mark Oaten is one of the Young Turks of the Liberal Democrats. Elected in 1997 and still in his mid-thirties, the Cabinet Office spokesman and chair of the parliamentary party is one of the new breed of Lib Dems: restless over third party status, impatient to forge ahead.

Tired and out of date ... crude and simplistic

Mark Oaten MP on Lib Dem policy of a penny on income tax

He used to be a Lib-Lab "Project" man, but purely for instrumental purposes rather than out of any passion for former leader Paddy Ashdown's vision of healing the breach between Britain's two centre-left parties.

"It seemed the best show in town," Oaten says. "It isn't now." Getting to share some of New Labour's limelight has been displaced by "us getting into a position of being the official opposition and going for the number one prize ourselves".

The Winchester MP is something of an outrider for a new project now: moving his party into the space vacated by the Conservative shift to the right under Iain Duncan Smith.

Time to shift focus

A vocal advocate of realigning the Liberal Democrats, Oaten argues that now is the time for his party to vigorously refocus its traditional emphasis on increased taxes for more spending on public services.

The Lib-Lab project as pursued by Paddy Ashdown has had its day, says Mark Oaten

The electoral mathematics appear to be on his side. In 44 of the Lib Dems' 52 seats, they face Tory challengers. In the vast majority of the seats where the Lib Dems are realistic challengers, it is sitting Conservative MPs they are chasing - and Tory voters they need to win over.

To capitalise on this psephological landscape Oaten believes his party must start sounding more Tory, "rather than like a left-wing party".

Tony Blair will not, Oaten predicts, deliver on the public services; the voters will withdraw their trust from him, but won't extend it to a Duncan Smith-led Tory Party. "So for us there's an enormous opportunity - but we've got to define ourselves very clearly."

'Time is running out'

Oaten's pendulum-swing theory of British politics holds that the turning point from Labour is at hand.

He's got enough people like me around him who are going to do a bit of pushing and shoving - to ride the bike a little bit ahead and then come back

Mark Oaten on Charles Kennedy

He sees Mr Blair winning a third term and "at this stage of the next parliament, the pendulum will be ready to swing", making the Lib Dems the official opposition - if, and it is a crucial if, his party starts readying itself now.

"So time is running out for our party," warns Oaten. "Because if we're going to be there to inherit and stop it swinging to the Conservatives, now is the time to start the preparations."

Conservatives are alive to the threat. Within weeks of the election Francis Maude warned "we run the risk, after the next election, of becoming the third party". Tory headquarters is setting up a special unit dedicated to attacking the Lib Dems.

Seeking dragons to slay

Thanks to Labour's move rightwards over recent years, the Lib Dems are seen as the more left-wing of the two. It is an image Oaten is anxious to shake off as a prerequisite to the realignment he sees as essential to the party's progress.

Iain Duncan Smith's leadership moves the Tories to the right

According Oaten, the Lib Dems lack the symbolic dragons that Labour leaders have in the past found useful to slay.

But the party does have a comprehensive review, launched by Charles Kennedy after the election, of its policies on the public services. Oaten hopes it will serve a similar purpose.

"We haven't got a Clause Four, Militants or rot at the core of the party," he says.

"Oddly enough, if we did it might be helpful because we could then make a big demonstration of tackling them and the public could then engage in what [the review] was about."

"By March," he predicts, "you'll begin to see the development of something I hope quite distinctive which will be both tough and tender, which journalists can say puts us to the right of Labour."

He forecasts the review will end up "saying some of the tough, difficult things about looking at private sector involvement, maybe at NHS rationing".

The tender component will include maintaining the Lib Dem tradition of tackling issues that the other parties tend only to later catch up on - like relaxing the laws on cannabis.

Goodbye to the penny on tax?

The nearest thing the party does have to a slayable dragon is the policy of raising income tax by a penny for increased spending on public services.

The NHS is a key political battleground for the three main parties

A decade old, it was developed in the immediate post-Thatcher era. It has become, after support for proportional representation, the policy voters most closely identify with the Lib Dems.

Previous bids to tinker with it have been met with deep suspicion by party activists. But Oaten believes it has had its day.

"It's an extraordinarily important symbol about wanting to get public services right and wanting to be honest with the electorate," he says. "[But] those are the important things, not the penny itself."

The policy, he feels, is seen as "tired and out of date".

Bumpy ride ahead

But he expects the review to retain a demonstration of the party's commitment to increasing spending through tax.

Charles Kennedy: Mark Oaten is close to him and intends to keep "pushing and shoving"

"I suspect where we'll end up is having a policy which is not as crude and simplistic as having a penny on income tax to pay for increased spending, but perhaps a change in national insurance looking at some sort of specific health tax."

Oaten knows the repositioning he sees as inevitable means a bumpy ride ahead for the Lib Dems. "But no more bumpy for us than the other parties," he says, pointing out that Labour and the Tories both have their own problems on health and education.

And though there may be internal trouble ahead, he is confident Charles Kennedy - Oaten was his parliamentary aide before the last election and remains close to him - won't quail from taking the Lib Dems through it to a realistic chance of breaking out of the third party ghetto at Westminster.

"He's got enough people like me around him who are going to do a bit of pushing and shoving - to ride the bike a little bit ahead and then come back," he says. "I think that works well."