Leading businessman Sir John Banham – who occupied a key public post during Margaret Thatcher's controversial reform of local government – said he had "nothing but admiration" for what she achieved for Britain.
Sir John, who grew up in Cornwall and now lives in Penwith, was the first controller of the Audit Commission, set up by Mrs Thatcher, from 1983 to 1987.
They were watershed years in the relationship between central and local government, with widespread reform culminating in the introduction of the ill-fated poll tax in 1990.
"Most people alive today have no concept of what life was like when she took office," Sir John told the Western Morning News.
"Inflation was running riot, the unions were running the country and the only real question was how fast we were going to decline both economically and socially. Almost single-handedly, I believe, she turned all that around.
"The idea that inflation would be at 2%, that we would have an independent Bank of England, that no-one knows who the head of the engineering union is and pays little heed to the TUC, is down to her."
In 1985-86, during Sir John's tenure, the commission led the inquiry into the so-called "rate-capping rebellion".
It ended with councillors from Lambeth and Liverpool, including deputy leader Derek Hatton, being surcharged and banned from office.
"I was the head of the Audit Commission when we imposed the surcharge," Sir John added. "Derek Hatton is in the dustbin of history whereas Mrs Thatcher's reputation, I very much hope, as a really great leader of this country will last."
Sir John, who said Mrs Thatcher always regarded him "as slightly pink politically", said she was "incredibly courteous" and "much more cautious than most people would think". But he added: "I did have some serious disagreements with her, not least about the failure to get inflation under control properly.
"I didn't think the poll tax was sensible at all and there were much better ways of getting to where we all wanted to get to. I don't think she liked such a key policy being challenged."
He added: "When I did have run-ins with her, as I did on occasion, it never got personal and that is a great characteristic of a very good leader."
Years earlier, Sir John had been asked by the Wilson government to assess the future of Britain's car making industry.
"Some said I should simply have handed in a blank sheet of paper because it had no future," Sir John, who was director general of the Confederation of British Industry from 1987 to 1992, said.
"There were 20 car manufacturers in Europe and the bottom six in terms of productivity were all in Britain. We still have 20 car manufacturers in Europe and the top six are all now from Britain.
"Until she came along, the whole idea that Britain might become the most successful car manufacturing country in Europe would have been laughable."
Sir John said she was a "remarkable woman", adding: "I have nothing but admiration for her and what she achieved."