The late Russell Johnston addressing a thinly attended annual conference in the 1970s of the Scottish Liberal Party of which he was then the Leader told a relieved audience “To be a Liberal and to know it is enough”. In the party’s famine of the time – only three Scottish MPs and opinion polls struggling to reach eight percent it was about as comforting as he could afford to be. Survival was everything.

Fast forward to 2009 – sixty three MPs at Westminster, a young charismatic leader, Cable the king of the airwaves, and twenty two per cent in two recent opinion polls. “To be Liberal and to know it…” simply is not enough.

With increased resources, MPs from Shetland to the Scilly Isles, and control of great cities like Liverpool and Newcastle there is opportunity. Along with opportunity usually goes obligation, but in the present febrile political circumstances the distinction maybe academic.

What is clear is that liberalism has never been more needed. The long steady march to the right which began for the Labour Party in 1997 under Tony Blair who found no contradiction between “Because it’s the right thing to do” and “If it works we’ll do it” may have been slowed under Gordon Brown. But the milestones of that journey are there for all to see. Forty two days detention without trial has been shelved but not abandoned. Identity cards are still on the agenda. Intrusive surveillance and unfettered access to personal data are now available to the least significant public authority.

A liberal government would never have embarked upon them and a new prime minister claiming liberal credentials would have abandoned them. Privately Labour backbenchers repent of their earlier support but dare not force the government to depart from legislation which undermines jury trial and restricts the freedom of the coroner.

Ministers extol human rights as these same rights are systematically dismantled by these same ministers. It is only one paradox but a powerful one that the protection of the citizen depends upon the illiberally constituted House of Lords.

This is a government which in its time has allowed office cleaners to pay a higher rate of tax than the people whose offices they clean; colluded with the Tories to try to exempt MPs from freedom of information; and halted a criminal investigation into allegations of corruption in arms sales to placate commercial interests. This is not a liberal government.

And what of the blue corner? What do you want? “Compassionate Conservatives”, “Liberal Conservatives” or “Progressive Conservatives”? You can have them all. This is an opposition party that voted for Iraq but now wants an inquiry in to it, an opposition party which whatever temporary epithet you apply to it is still a conservative party. It may have got rid of its toxic waste but in its heart you know it is a party of the right.

So how can liberalism triumph? First, you cannot be a part time liberal. Take faith, for example, a truly liberal society guarantees the freedom of all religions but accepts the tyranny of none. Our citizens must be free to live without threat or fear, free to say the things, write the words, and live the lives they choose. Will that offend some people? Of course, it will but that is a price worth paying.

Second, we must roll back the administration of an over mighty state by deleting many of the more than three thousand new crimes created since nineteen ninety seven; by a presumption against restrictions on freedom; and by effecting a new constitutional settlement which guarantees the rights of our citizens in a Bill of Rights to complement the European Convention.

But, we must also show liberalism to be practical and not just conceptual. Liberalism must mean something to single parents, the sick, the elderly and the disadvantaged.

The great liberal Beveridge in the language of his time identified five giants to slay, Want, Disease, Ignorance, Squalor and Idleness. Modern liberals should now lead the fight for five freedoms; we need the freedom born of opportunity, the freedom born of good health, the freedom of personal security, the freedom of prosperity for all, and the freedom of a clean environment. These are the practical freedoms of a liberal society. To know them is not enough. To achieve them is what is needed.

Sir Menzies Campbell is a former leader of the Liberal Democrats