Current Tory policy chief Oliver Letwin urged Thatcher to press ahead with the viciously iniquitous poll tax in the 1980s despite warnings from leading ministers that it would be politically “catastrophic,” newly released documents reveal.

Papers released by the National Archives in Kew show that Mr Letwin — then an adviser in the No 10 policy unit — helped to convince the prime minister to use Scotland as a testing ground for the new tax.

Chancellor Nigel Lawson was one of those opposed to the introduction, warning that the whole scheme would be “completely unworkable and politically catastrophic.”

Yet despite such clear warnings Mr Letwin — now a Cabinet Office minister and David Cameron’s chief policy adviser — urged Thatcher to bloody-mindedly stick to the original plan, using Scotland as a “trailblazer.”

He advised: “No-one can say that you are being insufficiently radical, since you will be … trying out an extremely radical system in a significant part of the country.

“By the same token, no one can accuse you of being rash, since you will be reserving your options on domestic rates in England and Wales.”

The introduction of the poll tax sparked mass rioting and protests across Britain and helped bring about Thatcher’s political demise.

Labour shadow Cabinet Office minister Jonathan Ashworth said: “Oliver Letwin was a key architect of the poll tax, so enthusiastic about it he pressed Margaret Thatcher to push ahead with its introduction.

“Over the years he has called for further privatisation of the NHS and for public expenditure at 35 per cent of gross domestic product.

“Today he is David Cameron’s policy chief at the heart of his government. It seems that the Tory Party never changes.”?