Slowly but surely, the Lib Dems are finding a distinctive political voice

The Liberal Democrats are maturing into a serious and credible political force. The pre-election manifesto launched by Charles Kennedy yesterday was slick and professionally presented. More importantly, the mini manifesto was also a radical programme fleshed out by a fair amount of detail. It was not just a collection of vacuous soundbites.

The Liberal Democrats are maturing into a serious and credible political force. The pre-election manifesto launched by Charles Kennedy yesterday was slick and professionally presented. More importantly, the mini manifesto was also a radical programme fleshed out by a fair amount of detail. It was not just a collection of vacuous soundbites.

The document highlights the party's more distinctive policies. Sensibly, the party proposes that some Whitehall departments, including the mighty Treasury, should be moved out of London and that the Department of Trade and Industry should be abolished altogether. They have interesting proposals for the de- centralisation of public services giving much greater control to local communities, removing the stifling targets imposed by the Government. The pre-election manifesto is also clear about the party's support for the new European constitution while urging further reforms. The programme is cleverly presented under the three themes of Freedom, Fairness and Trust. These values are not explicitly rooted on the political left or right of the spectrum but have a broad appeal.

Inevitably, plenty of questions arise from such a document. On the thorny issue of taxation, they advocate a local income tax and a new top rate of income tax for higher earners that would raise money for some of their spending proposals. The money raised would pay for a lot of attractive, but expensive, policies, such as abolishing any charges for long-term residential care. Opponents will argue with some justification that the party is being optimistic about the amount of cash a higher rate of tax would produce. Indeed, it would be well advised to scrap this policy, which smacks of gesture politics.

The abolition of a property tax is, in many ways, a sensible proposal in a country with often wildly fluctuating house prices. The current Council Tax is unfair on low earners who own homes that have soared in value. Pensioners are especially vulnerable. Even so, a local income tax will be a daunting prospect for some middle-income earners, especially if councils are given the freedom to decide on the level of the bills. Switching local taxes is an awkward business especially for a party that opposes excessive intervention from central government. How could such a government keep any control on the level of local taxation?

But on the whole the party's policies have been carefully costed. The tone of the document is not excessively idealistic, yet it has a distinctive edge. Mr Kennedy is benefiting from the input of senior Liberal Democrat MPs, such as his thoughtful shadow Chancellor, Vincent Cable, who have a greater interest in policy detail than some of their predecessors. They have made an underestimated difference to the party's broader pitch. Under the leadership of Paddy Ashdown the Liberal Democrats mattered because of their leader's energy and his relationship with Tony Blair rather than for their policy programme. Under Mr Kennedy, they are becoming more of a political force in their own right.

Mr Blair has created political space by his cautious defensiveness on several policy fronts. Often he is more focused on out-manoeuvring the Conservatives than promoting radical policies. In response, the Conservatives have moved further to the right, which leaves the Liberal Democrats with an opportunity to develop distinctive policies.

They still have a long way to go before they can claim to be an alternative government. The performance of their parliamentary team is erratic. They benefit from a lack of media scrutiny over their policies. There are some marked internal tensions over the role of the state in the provision of services.

Even so, recent polls suggest that support for the Liberal Democrats is growing significantly - and it is not entirely due to their stance opposing the war in Iraq. The two bigger parties face a third political force that is not only becoming more credible, but more popular also. And this could yet make the general election more interesting than many expect.