When the Liberal Harry Willcock refused to produce an ID card in 1950 he uttered: "I'm a liberal and I'm against this sort of thing." His successful appeal against his subsequent conviction led to the scrapping of the-then Labour Government's ID card system.

Harry Willcock's mild but determined statement demonstrated his instinctive understanding that the excesses of the state need to be curtailed, and that it is a liberal's duty to curtail them.

When the last Labour Government proposed the creation of an ID database and ID cards, SNP MPs and MSPs joined Liberal Democrats in opposing those plans.

What a difference a few years makes. Now, the SNP Government wants to expand the NHS Central Register in Scotland from a health records system into an intrusive ID database.

These alarming plans would mean every person could be tracked by 120 public agencies through the use of persistent identifier known as a Unique Citizen Reference Number (UCRN). It's like a clubcard, except the only bonus you get is when civil servants don't lose your personal information. The bodies proposed to have access to the expanded database include the Royal Botanic Gardens and Quality Meat Scotland. The Information Commissioner rightly noted that the Scottish Government's consultation didn't even attempt to explain why each of these bodies needed such broad ranging personal details to function.

This explanation is required by UK and EU data protection laws. It's required because it ensures that our civil liberties are protected against powerful states hell bent on "function creep". As an individual, the burden is on the state to justify why it needs our private information, and not the other way round.

The risk the SNP's super ID database poses to our privacy is clear. Expanding the UCRN as a one-stop shop clubcard number means that every interaction people have with public bodies could be identified. It opens up the possibility of data sharing and data mining on an industrial scale across the public sector, without our consent.

Stories about secure IT systems being hacked feature regularly in the media. Earlier this month, Police Scotland admitted that 20,000 stop-and-search data records had been lost because someone pressed the wrong button.

In a recent interview, Deputy First Minister John Swinney said: "The Government believes in the privacy of its citizens, we will protect personal privacy."

The Scottish Government consultation on these proposals glossed over many of the risks associated with their plans and simply ignores others altogether. By linking these major changes to legislation passed years ago, the SNP are avoiding proper parliamentary scrutiny.

During a recent television interview discussing the plans for the creation of a new super ID database, I was accused of trying to exploit this issue for political ends by an SNP backbencher.

Presumably, he would not accuse the Scottish Council of Voluntary Organisations of the same offence. It has come out against the database plans and warned SNP ministers about the dangers the plans pose to our privacy.

Now the Information Commissioner's Office has joined the debate, warning that what the SNP Government proposes could breach UK and EU data protection laws. He said proposals to create a national identity number warrant full debate and scrutiny. I agree.

The consultation on these plans has been shown to be completely inadequate. The very thought of a Holyrood committee nodding these through would send shivers down the spine of any self-respecting democrat.

Today, Liberal Democrats at the Scottish Parliament will force a vote on these plans and call on the SNP to respect the views of the ICO and others who want to see these proposals laid out in primary legislation. This must come with full privacy assessments and at least some alternatives to this bureaucratic, shove-everything-in-a-filing-cabinet approach.

Proposals that would pose such a fundamental risk to our privacy deserve nothing less.