The assisted places scheme, the first political attempt to subsidise pupils from modest backgrounds to attend fee-paying schools, was an early flagship policy of the Thatcher administration when it came to power in May 1979. It was also an early test of relationships between the different political needs of England and Scotland, which had become bruised after the defeat of the devolution referendum under the previous Callaghan government earlier that year.
In a submission to Thatcher's first Scottish education minister, the irrepressible Alex Fletcher, officials said it was "not entirely wrong" for critics to say the assisted places scheme was essentially English and "ill-adapted to Scottish traditions". They pointed out that there were 20 fee-paying schools in England and Wales for every one in Scotland.
The submission to Mr Fletcher, dated May 2, 1980, told him in no uncertain terms that there was "more opposition to the scheme than support for it". This did not just come from the usual suspects in the local authorities and the teaching unions. "More surprisingly," he was told, "there is a strong body of opinion against the scheme amongst the grant-aided secondary schools themselves."
This was because the 21 schools believed their days were numbered, since the scheme would create a market by providing direct assistance to the pupil as opposed to the previous form of a block grant to the school.
There was also considerable tension between the schools' desire to make sure their own primary pupils benefited, rather than those from the state sector who were the Government's target. Even the influential Edinburgh Merchant Company, which ran the prestigious George Watson's, Stewart's Melville and Mary Erskine schools in the capital and was the Government's most positive supporter, threatened not to take part if its schools were forced to take in too many public-sector pupils.
The opposition, officials suggested, "is no doubt attributable to an innate dislike (especially on the part of girls' schools) of the idea of receiving a large number of children from low income families".
Ministers were eventually forced to scale down what officials came to call the "unpopular" scheme, starting with 600-750 places rather than the 1,200-1,500 originally envisaged and phasing it in over five years from the 1981-82 session.
There was particular sensitivity to charges that it was "creaming off" pupils from state schools and, in some tortuous exchanges dealing with the means test for deciding which parents should be eligible, to the accusation that it was being too generous to middle-class families.
At one point, Bill Fiddes, the leading official dealing with the scheme in the Scottish Education Department, tentatively suggested to his boss, Pat Cox, that "the scheme was so unpopular in Scotland that it should simply be abandoned" - before concluding with a probably nervous addendum: "We decided that this would be politically unacceptable." There is no record of any response from the formidable Ms Cox.
After much to-ing and fro-ing between the Department of Education and Science in London and the SED in Edinburgh, there was a general acceptance that the scheme did not have to be exactly the same north and south of the border. "Scotland was sufficiently different to make divergence tolerable," one memo explained.
The assisted places scheme eventually went from strength to strength until 1997 when the Blair Government, enthusiastically cheered on north of the border by its Scottish Education Minister Brian Wilson, decided - to nobody's great surprise - to axe it.