Major parties in a spin after Clegg's triumph

There's a useful aphorism from the United States. The winners grin; the losers spin.

So it has been since the first British televised leaders' debate on Friday gave an electric jolt to a hitherto low-wattage campaign.

Peter Mandelson, Alastair Campbell and the rest of the Labour spin doctors and truth surgeons have tried to present the bout as a victory for their candidate on "substance". Translation: Gordon Brown, the Prime Minister, made his characteristic, elemental error of thinking that the way to the nation's heart is the robotic recital of lists of statistics.

Minister Alan Johnson suggested that it did not matter if the Prime Minister was a leaden performer because "this is not a popularity contest". But popularity contest is exactly what it is.

Over in the Tory spin world, leader David Cameron's propagandists have been shrugging about the viewing figures even though more than 9 million was a highly respectable audience. Conservative spin-meisters say many voters didn't tune in and the winners of US presidential debates don't always win the actual election. They are not points which would have interested the Conservatives if they were happy with the performance of their leader.

And the Lib Dems? They, of course, are the ones wearing the grins - ear-to-ear, cheek-aching grins - with their leader's triumph. His pre-debate negotiators created a platform for victory by securing even airtime and status with his two rivals, the like of which has never been enjoyed by any previous leader of the third party.

Having got his chance, Nick Clegg did not blow it. He could have looked incidental and marginalised in the company of the other two. That is his weekly fate at Prime Minister's questions in the House of Commons.

His skill was to use the debate to make himself look the equal of Brown and Cameron as well as a personable, reasonable and refreshing alternative to both of them. Many Tories are cursing their leader for gifting the Lib Dem this opportunity to shine.

Clegg used his prep time much more effectively. He had the smarter grasp of how to use the artificiality of a TV format to project himself as authentic. It is Debating for Beginners to address questioners by their Christian names in order to establish a rapport. Yet only Clegg did this from the beginning and his rivals looked like poor mimics when they started to copy him. Neither was his match at looking directly into the camera in order to make a connection with the audience at home.

The Lib Dems spent a lot of time studying video of rehearsals to determine whether this would look creepy or attractive. The team who prepped Clegg was home-grown. The Lib Dems could not afford to import American consultants in the way that Labour and the Tories have. Stylistically, Clegg came over as more naturally British than either of his rivals.

Brown was the worst offender at trying to lever in jokes which were much too obviously pre-cooked. Cameron was the most painfully over-reliant on the American technique of using an anecdote to make a point. "I recently bumped into a Basildon mother of three with an ingrowing toenail and that is why I love the National Health Service."

The worst was the Tory leader's "I once met a black man". He was playing not to lose and straining too hard to seem prime ministerial, with the result that he looked anxious and sounded constipated.

There were deeper reasons for Clegg's victory. Brown came into the studio clunking the same ball and chain which he is forced to drag the entire length of the campaign trail. He is the unpopular leader of a Government that has been in power for 13 years. Cameron's baggage is the number of changing and sometimes conflicting positions he has adopted over the past four years.

Clegg had a simple, clear message that fitted with his wider campaign: Britain has been let down for decades by the other two.

His most resonant line was: "The more they attack each other, the more they exactly sound the same." That jibe was clearly pre-prepared, but he inserted it at a point where it seemed a spontaneous response to his bickering rivals.

A "plague on both your houses" has been the traditional tune of third-party leaders . It is working so well for Clegg because the voters are now particularly receptive to that song. The parliamentary expenses scandal has intensified public alienation from establishment politics to the advantage of the leader who can present himself as an insurgent outsider.

Very senior Tories are now ruing their failure to develop a strategy for dealing with the Lib Dems before the campaign started. The Conservatives were complacent in assuming that they could simply squeeze the third party into irrelevance and cruise to victory on the slogan of change. They now have to deal with Clegg out-Daveing Cameron and presenting himself as the fresher and more sincere face of renewal.

The Lib Dems are keen to capitalise on this boost, but are wary of the hype for fear that it will set up Clegg to flop at next Friday's debate, which he goes into with greatly raised expectations.

Some Labour strategists have talked up Clegg's win because it diminished Cameron and disrupted the general media assumption that the Tories were heading for power.

A lift for the Lib Dems helps to secure those of their seats in southern England which previously looked lost to the Tories. That makes it harder for the Conservatives to achieve a parliamentary majority. This seemed welcome to Labour because their hopes of remaining in office repose in a hung Parliament. That was before the YouGov poll on Saturday which had the Lib Dems sucking support from both the other two.

We will need more evidence before we know whether this a brief spasm or a meaningful surge. But if the Lib Dems become the party with all the momentum, who knows what might happen?

Tory ambitions to win a majority now depend on putting the lid on the Lib Dems. Cameron's strategists are already arguing among themselves about how aggressively they should "take the fight" to Clegg. Their visceral instinct is to go for the Lib Dems as wet on crime, reckless on defence, soft on immigration and in love with Europe. The risk for the Tories is that this lures Cameron back on to failed Tory territory and will look like a lurch to the right which is repulsive to the liberal, centrist voters that he needs.

Tory Michael Gove patronised the Lib Dems as "outside the mainstream and a little bit eccentric". The trouble for the Tories and Labour is that being outside the mainstream does not look eccentric to the many voters distrustful of and disillusioned with the old duopoly. It looks jolly attractive.

- OBSERVER