A genuine three-party contest would be a tonic for our tired electoral system

If anyone still harboured doubts that the coming election will be at least a three-way contest, yesterday's crowded political schedule should have dispelled them for good. With the Liberal Democrats launching their "pre- manifesto", the Tories presenting the results of their tax and spending review, and Labour jamming between them a "pre-election" press conference, we find ourselves in the midst of what is being called a "pre-campaign" campaign. And the term is not vain. This is no phoney war; nor is it mere preliminary skirmishing. The battle for the hearts and minds of the British electorate is already under way.

If anyone still harboured doubts that the coming election will be at least a three-way contest, yesterday's crowded political schedule should have dispelled them for good. With the Liberal Democrats launching their "pre- manifesto", the Tories presenting the results of their tax and spending review, and Labour jamming between them a "pre-election" press conference, we find ourselves in the midst of what is being called a "pre-campaign" campaign. And the term is not vain. This is no phoney war; nor is it mere preliminary skirmishing. The battle for the hearts and minds of the British electorate is already under way.

The late decision of Labour to put its oar in yesterday showed how much it believes is already at stake. Campaigning lesson 101 from the Bill Clinton play-book is that nothing can be left to chance; nothing must go uncontested. Nor were the Liberal Democrats placed in any way at a disadvantage by the chance timing of their launch on the same day as the Tories' widely touted presentation of their £35bn spending cuts. The timing was a risk, but it was also an opportunity for them to present themselves as the genuine party of opposition. It was an opportunity that Charles Kennedy grasped with both hands.

Mr Kennedy has not always presented himself, or his party's policies, to best effect. Yesterday, though, we saw an incisive, sharply focused leader; one who carried conviction. Compared with the almost apologetic double-act of Michael Howard and Oliver Letwin later in the day, Mr Kennedy's performance suggested that on policies and personality, if not on experience and glitz, at least someone has the will to give the voters a real choice.

In key respects, the Liberal Democrats' claim to offer a genuine alternative to both Labour and Tories is no idle boast. The only party to have opposed the war in Iraq, they are entirely justified in claiming the high ground - political and moral - on this issue. They are the only party to oppose the introduction of ID cards - a libertarian stance which a more principled and less scared Tory party might have adopted. Nor is this the only area in which they have resisted the temptation to court the "fear" vote. They also oppose illiberal changes to provisions for immigration and asylum. Politically, these are courageous positions to take. They are the credentials of a real opposition.

We dissent from some of their tax and spending priorities, including their plan to replace council tax with a local income tax and a higher tax rate on upper earners. We fear, too, that there is no real alternative to top-up fees for university tuition, despite their unpopularity. But there is certainly room to raise money from reductions in the government payroll, which has ballooned in Labour's second term. And Mr Kennedy's boldly direct approach has much to recommend it: "With us, [the voters] will be presented with a straightforward package which will have a price tag attached, and we will invite them to decide." You cannot get fairer than that.

In one significant respect, the Liberal Democrats are at an advantage in the coming campaign. Unlike the Labour Party or the Conservatives, they have long been accustomed to fighting on both flanks. They know how to push forward while protecting their backs. For both Labour and Tory leaders, this is new and dangerous territory. The result is a confusion of political gymnastics: both try to lean simultaneously to the right on crime and immigration and to the left on social issues, while stressing their intentions to maintain fiscal discipline. And these contortions must be performed while ducking to limit damage from their support for a grievously ill-advised war.

This gives Charles Kennedy his chance. As John Curtice argues today, the continuing weakness of the Conservatives may not necessarily translate into another walkover for Labour. The mathematics may turn out to be more complicated than that. This election will, to quote Mr Kennedy, "be real three-party politics". It will be all the better for that.