GENERATIONS of ministers were warned not to introduce a poll tax before the Conservatives finally pushed ahead regardless in the late 1980s, according to previously secret files released by the National Records of Scotland.
A letter from a Scottish Office mandarin, written as John Major's Tory government wrestled with a public backlash to the charge in 1991, suggests successive governments were advised against it.
Collecting a tax on individuals was "bound to be infinitely more difficult" than collecting one based on property or income, the memo said.
The comments were made by the under secretary at the Scottish Home and Health Department, James Fraser.
Officially known as the community charge, the poll tax replaced domestic rates with a flat rate levy for council services, with millionaires in mansions paying the same as pensioners in flats.
It was introduced in Scotland from April 1, 1989 and a year later in England and Wales, a difference which fuelled claims that Scotland was being used as a guinea pig.
Instantly unpopular, the tax sparked a mass non-payment campaign which launched the political career of Tommy Sheridan, helped topple Margaret Thatcher in 1990, and forced John Major to replace it with council tax in 1993.
In August 1991, Fraser wrote to a junior civil servant in the Scottish Local Government Finance Group expressing concern over "unnecessarily high levels of imprisonment for fine default" as a result of people refusing to pay the tax.
Noting "grounds for optimism" that the incoming council tax should be easier to collect, Fraser recalled how civil servants had long advised politicians against a poll tax.
He wrote: "In former days we advised Ministers as strongly against a poll tax as no doubt our successors did before it was introduced; collection of a tax levied on individuals at large is bound to be infinitely more difficult to collect than one related in some way to heritable property, income, sales or imports."
Fraser, who has since retired, said: "I think anyone could see it was a lousy idea. I don't think it found much favour in Scotland."
Indeed, other files show Cabinet-level discussions about high levels of non-payment in Scotland.
In November 1991, ministers were told English councils had collected 90% of the tax for 1990-91, while Scottish councils had collected 78%.
"Collection was undoubtedly poorest in Scotland," the meeting noted, meaning charges for the following year "might end up 10% higher than in England" in order to cover the shortfall.
To avoid a vicious circle of high charges, ministers considered giving Scottish councils an extra £25 million grant, because of the "political difficulties which might ensue in Scotland".
The files reveal a long-running argument over whether the poll tax was technically a tax at all.
In 1988, Department of Environment officials said their legal advice "suggested that the community charge in England and Wales was not legally a tax", as it was neither a traditional tax on income or a tax on expenditure.
But the Cabinet Office told the Treasury that "it seems to us that there is no doubt that the community charge should be classified as a tax", citing a United Nations definition.