PETER OBORNE: The Great Liberal deception

Updated: 04:11 EDT, 20 April 2010

Liberal Democrat leader Nick Clegg

Despite the brilliant performance by Lib Dem leader Nick Clegg in last week's TV election debate, most commentators have dismissed his party's subsequent surge in the opinion polls (in two cases putting them ahead of the Tories and Labour) and predicted that life will return to normal by May 6.

However, I believe that these experts are wrong and that with voters' utter disenchantment with politics, Clegg has tapped the public mood in a way nobody else can. So let me try a daring mental experiment and assume that the polls will remain in the Lib Dems' favour.

We will have to reshape all of our assumptions, not just about this general election, but also about the long-term future of British politics. The most obvious consequence is that Clegg has dramatically stolen David Cameron's most powerful claim to power - that he alone can be the agent of change after 13 years of disastrous New Labour rule.

His hopes of victory on May 6 had been based on the belief that the Tories can win back the dozens of seats across southern and western England that have fallen to the Lib Dems over the past 20 years.

That now looks out of the question. Indeed, we must contemplate the possibility that Cameron himself could be finished as a political force.

Five years ago he memorably leant across the Despatch Box in the Commons and devastatingly told the then Labour PM Tony Blair: 'You were the future once.'

Now, Clegg has in effect said exactly the same thing to him. Bear in mind that the weekend polls did not just indicate a surge in Lib Dem ratings but also cast a devastating verdict on Cameron's personality.

Voters scored him very low indeed for cherished assets such as honesty and charisma - and alarmingly high for slickness and poshness.

Those who know Cameron's true qualities are entitled to contest the judgment of the voters as desperately unfair. But that's politics. Nor is the damage done to Cameron the only effect on the Tory Party.

Even if the Tories still scrape home in the election, the prospect of George Osborne, Cameron's bosom ally, becoming Chancellor has dramatically receded.

Instead, the hugely popular Lib Dem Treasury spokesman Vince Cable must be favourite for the position if a hung parliament, with no party holding the overall majority, is the outcome (which is increasingly likely).

For the Lib Dems would hold the balance of power, with neither of the two main parties - whoever wins the most number of seats - able to govern without Clegg's support.

As such, although he would not have a majority of seats in the Commons, Clegg would nevertheless be seen as the moral victor of the election and feel entitled to make powerful demands in return for his support to whichever party would do a deal with him, including an ability to dictate some key Cabinet appointments.

Above all, he would want Cable as Chancellor - something both Brown and Cameron would be grateful to concede. On top of this, Clegg would undoubtedly insist on the introduction of proportional representation to replace the current first-past-the-post voting system in general elections. This would completely change the way Britain is governed.

Gone would be the system of one party rule that has endured for the past 200 years. Advocates of PR say it will stop the Tories or Labour from forming governments despite only ever obtaining a minority of the national vote.

Instead, Britain would have coalition governments formed of two or three rival parties - as exist in most of continental Europe.

The result would mean it is highly unlikely either Labour or the Tories would ever govern Britain again on their own. For this reason, Cameron will find it difficult to strike a post-election deal with Clegg.

Therefore, in the event of a hung parliament on May 7, a Liberal-Labour coalition is most likely. Indeed, Labour strategists are talking about 'Chancellor Cable', Clegg is being mentioned as a possible Leader of the House and a Bill promising proportional representation would be top of any legislative agenda.

It comes as no surprise that the main supporter of such a deal is Peter Mandelson, for whom it would be the final realisation of the dream that took him and Blair into politics two decades ago.

The pair have never hidden their grand ambition for British politics to build a centre Left alliance between the Liberal and Labour parties that would shut the Conservatives out of power for ever.

This explains the extraordinary scenes on Thursday night when Mandelson was extolling Nick Clegg's performance in the leaders' TV debate.

The truth is that Mandelson - who would also be happy to see the Liberals force through his own vision of closer European ties - is prepared to sacrifice both the short-term interests of the Labour Party and for that matter Gordon Brown to serve his long-term vision.

It is against this front that David Cameron is now battling. Not only is he fighting to save his own political career, he is also struggling to save the Conservative Party itself, and everything it stands for. At the moment, he is losing the battle. Yet all is not yet over.

Cameron has shown again and again that he is never more resourceful or more dangerous than when his back is against the wall. So how can he fight back? First, he must make voters realise that Clegg is part of the old system of corrupt politics that he pretends to be apart from.  

For example, Clegg claimed that 'all my life' he had opposed the rotten nature of the Westminster system.

However, this was an audacious fib. In fact, he has a background as a Westminster lobbyist with the firm GJW, where he worked as an account executive for 18 months. (Something he has omitted from his curriculum vitae on the Lib Dem website).

Also, after his spell with GJW, he worked for the Brussels office of the European Commissioner Sir Leon Brittan.

In truth, Clegg is a prime specimen of the British political class who has reinvented himself as a rebel and an outsider. Nor is his party more decent and honest than other political parties, as Clegg suggests.

On the contrary, many Lib Dem MPs have been shameless beneficiaries from the expenses scandal. What's more, the party has yet to repay £2.5 million it received from its largest donor, a notorious fraudster called Michael Brown.

However, the danger for Cameron is that by attacking Clegg he may worsen matters by compounding the image of him representing the 'nasty' culture that the Lib Dems claim to want to clean up.

At a time when the two-party system is so morally tainted, Clegg is brilliantly exploiting this crisis in our democracy. Every generation or so, British political life is punctuated by a seismic event which changes the entire landscape.

One such moment was the election of a Scottish trade unionist, Keir Hardie, as the Labour Party MP for Merthyr Tydfil in the 1900 general election.

Few recognised what was happening at the time, but within two decades the Liberal Party, which had dominated politics during the Victorian era, was finished as a ruling class.

Another such event was Britain's humiliating eviction from the Exchange Rate Mechanism on Black Wednesday 1992.

On that day the Conservative Party was destroyed as a governing force and has never won an election since.

Though it is too early to say for certain, it may well be that historians will look back on 90 minutes of prime-time TV last week and conclude that they changed British politics for good - triggering a tsunami which wiped out the system of two-party politics.

In its place, we may be looking forward to a revolution in the form of an experiment in European-style consensus government. We will know a good part of the answer on May 7.