The debate over who should succeed Sir Menzies Campbell as leader of the Liberal Democrats is now well under way. Martin Kettle is correct to say that this debate should not be dismissed as a beauty contest between two ostensibly identical candidates.

For me, the debate is a choice between an excellent strategist (Huhne) and a brilliant communicator (Clegg). I remain undecided between the two; I would argue that both are vitally important.

But in terms of strategy, the need for a clearer vision and policies that reflect that vision, the party needs to consider how it makes such decisions. In Sir Menzies' resignation letter, he wrote "I am convinced that the internal structures of the party need radical revision if we are to compete effectively against Labour and the Conservatives."

This was an issue for his predecessor as well. One of Charles Kennedy's first acts as leader was to call for the party to adopt one-member-one-vote for elections to internal committees (the party has always had OMOV for elections to its Leader and President, but the majority of the Federal Executive, Federal Policy Committee and Federal Conference Committee are elected by the representatives of local parties who have a vote at party conferences). This idea fell flat on its face when an all member survey found that a clear majority of members opposed the change. But even towards the end of his leadership, Kennedy talked of his frustrations with the party's policy making process.

Earlier this week on the Unlock Democracy website, Peter Facey summarised the three main party's systems of internal democracy as: "the Liberal Democrat conference thinks it makes policy and it does, the Labour conference thinks it makes policy but doesn't and the Conservative conference knows it doesn't make policy and doesn't care". I would add a further distinction: the Labour party deliberates but resolves nothing, while the Liberal Democrats make resolutions but don't deliberate.

That isn't to say that the quality of debate at Lib Dem conference isn't high; the problem is the level of debate up until that point. "Consultation" such as it is involves a three hour debate on the Sunday morning before party conferences followed by a narrow window of opportunity to make written submissions. In many cases the working group will have already pretty much decided 90% of the paper by that point. Local parties as an entity contribute very little to policy overall; very few have regular policy discussions, let alone formal ones which actually feed into the process. Indeed, Unlock Democracy research suggests that of the three main parties, the Liberals discuss policy less than either of the other two at a local level, despite the much greater power their local parties theoretically wield.

At the other end, we have a system which a significant proportion of our frontbenchers hate and bypass at every opportunity. But it is also incredibly inflexible in an age of 24-hour rolling news, and while it is fine for a party content with permanent opposition, I'm not sure it is sufficiently robust enough to survive government.

The latter question was what exercised the modernisers of the Labour Party in the mid-90s. Partnership in Power, which under Gordon Brown has now reached its apotheosis, was the result. The problem with this system though is that while CLPs can contribute to it until the cows come home, they have no real input to give even the gentlest of steers to party direction. It is anathema for most Lib Dems to go down that route; surely however there must be another option?

In my view, one of the main issues is to decouple short term policy commitments, which by necessity need to change relatively frequently according to the political weather, and the long term vision of where the party would like to take the nation, which should be relatively inflexible. The Liberal Democrats have always been very poor at developing a coherent vision, although this has been improving in recent years. But we continue to pass policy in which the two are jumbled up and even contradict each other.

Perhaps the party conference should be less precious about its role in determining the former, in exchange for a stronger grip on the latter? Party conference would set out the vision, including overall long term policy objectives which couldn't be introduced by a party in its first term of office; the Parliamentary Party and the Party's Policy Committee would have overall responsibility for determining short term policy objectives, including the manifesto itself, although conference would continue to have an advisory role. Crucially however, the policy would not be allowed to contradict the longer term vision. We could no longer have, for example, the situation whereby the party has a long term commitment to shift the burden of taxation off incomes and onto resource use, while having a short term policy to raise income tax. But we wouldn't be forced to call for tax cuts regardless of the economic situation.

In a very real sense, this is what we do now in practice anyway. No policy is guaranteed inclusion in the manifesto, the final draft of which can never be put in conference's hands for practical reasons. But by not drawing a clear distinction between the two we end up with a hodge-podge in which opportunism often trumps the underlying purpose of the party. While the result has been short term political gain, it has resulted in a veritable trashing of our own brand.

I admit that the distinction between vision and policy is not as clear cut as it could be, and that there are bound to be some grey areas that will cause difficulty. Ultimately, any system is only as good as the people who work inside of it. But I do think that a renewed emphasis on vision and purpose can only help a party struggling to eke out an identity in a crowded political arena. And allowing our senior politicians a greater role in tweaking and finessing our policy can only improve our dynamism and ability to remain relevant.