Perhaps you don’t sit around with your friends swapping anecdotes about the Liberals. Just guessing. And that means you haven’t heard about the mattress.

Back when the Liberal Party was fighting for control of Liverpool, so the story goes, they purchased a smelly old mattress. A group of Liberals would drive around, carrying this mouldy bedding in the back of a van. And then they would dump it in the alley behind a row of houses.

A couple of nights later, the group would go canvassing: “Have you any local problems your local Liberals can deal with?” And the residents would reply that, as the matter of fact, there were. Someone had dumped an old mattress in the alley behind their house. Could the Liberals do something about it, please?

At the end of the evening, they would stuff it back in the van, drive off and dump it somewhere else.

Anyone who has been a political activist has a stock of such stories. The one about the bypass, for instance. During by-election campaigns, the Liberals would turn up at their opponents’ public meetings and wait for the speeches to wind up. Then in the question period they would ask the hapless out-of-town Tory or Labour candidate what was their view of the bypass issue. The candidate would stutter through an embarassing answer, unaware that there wasn’t a bypass issue.

These stories may have been embellished by constant retelling. But they are a testament to something that all political professionals will acknowledge. At the local level Liberal Democrat campaigns are witty, shrewd, hard-nosed, even ruthless and often successful.

Which makes it baffling that nationally their strategy has so often been weedy, contradictory and a flop.

I wonder if it has struck the party faithful down in Bournemouth what a catastrophic failure it would be if the next election result reflected current opinion polls. It would mean that the strategy of being a wedge in a hung Parliament had totally failed. Britain would have passed from an improbably large Labour victory to an improbably large Tory one, without stopping off for a hung Parliament along the way.

And this failed strategy will have lasted half a lifetime. The last time an election resulted in a hung Parliament was when Nick Clegg was 7 years old. By the time there is another opportunity he will be 47. The party cannot take refuge in the idea that they have been the hapless victim of maths and the election system. If they fail at the next election it is because they have lost support during a period not only of incredibly unpopular government, but also of unpopularity of the system they have spent years promising to change. Minor parties have profited and they haven’t.

So what should they do? Start putting strategy first. Strategy before mattresses, bypasses and local council by-elections, strategy before the interests of individual MPs, before passing political opportunity, before tactical advantage. And this is an urgent requirement because the great Liberal moment is at hand. The great Liberal moment is possibly just two years away.

In 2012, in all likelihood, there will be a Conservative government struggling with a huge fiscal deficit. The Tories will be cutting public spending, and the public may be turning on them. It having been assumed that cuts can be made merely by efficiency savings, the ferocity of the reductions might surprise voters. At the same time, it is quite likely that Labour will be moving left, possibly under a weak leader. The governing class of the centre Left, the people who served in ministries or ran quangos, will be feeling uncomfortable, disenfranchised, perhaps insulted.

In other words, the political scene may look remarkably as it did in 1981. And in 1981 the SDP was formed, building an alliance with the Liberals and temporarily sweeping all before it: 2012 could be the great Liberal moment. And the party can seize it if it begins to prepare now.

It should do two things. The first, and most important, is to realise that Mr Clegg’s stated strategic goal of taking over the centre Left is at odds with his tactic of targeting Labour seats at the next election. Labour retains sufficient regional strength that an attempt by the Liberal Democrats simply to wipe them out seems almost certain to fail. They may, to be sure, win a few seats in Labour areas next time. But, after that, progress will stall. And the targeting will have had a huge cost. It will make the sort of soft merger of the forces of the centre Left — the informal, coalition-in-all-but- name that the Liberals must hope to lead in a few years’ time — much harder to form.

With Liberals on the ground campaigning, deploying their mattresses in force against Labour MPs, co-operating with them will be seen as a tremendous act of betrayal. The rhetoric will become harder, the group allegiances stronger. Liberal Democrat strategy — their goal of leading the centre Left and what Mr Clegg calls a “progressive realignment” — must trump Liberal Democrat tactical advantage — picking off seats that seem vulnerable. Strategy demands that they become the main opponents of the Tories in the South, not the main opponents of Labour in the North. Even at this difficult time they should continue targeting the Tories in the South rather than Labour in North.

This, of course, is open to the objection that it involves underperforming at the next election, missing out on available votes. But it does not. For the second thing the Liberal Democrats must do is to target the most successful rising group in British politics. They need to win the support of people voting for the “others”.

Since the last election, Labour has gone down about ten points and the Conservatives up by about eight. In the meantime, the Liberal Democrats have gone down by about five points. These figures are explained by one more figure — “others” have risen by seven points. This is a terrible result for the party to contemplate. People are turning away from two-party politics, but not to them. If there is to be a Liberal moment, these people have to be won back.

The issues are obvious — disillusion with politicians, fury over expenses, a burning desire for change. All those Liberal causes — political reform, no more Punch and Judy, even proportional representation — that seemed arcane, irrelevant, risible, their time is now. For heaven’s sake, Liberals, the issues are right there under your noses. What’s the matter with you?

daniel.finkelstein@thetimes.co.uk

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