The Conservative Party led by Edward Heath won the 1970 general election, and Thatcher was appointed to the Cabinet as secretary of state for education and science.
Thatcher caused controversy when after only a few days in office she withdrew Labour's Circular 10/65 which attempted to force comprehensivisation, without going through a consultation progress.
 She was highly criticised for the speed in which she carried this out.
Consequently, she drafted her own new policy (Circular 10/70) which ensured that local authorities were not forced to go comprehensive.
Her new policy was not meant to stop the development of new comprehensives; she said: "We shall ... expect plans to be based on educational considerations rather than on the comprehensive principle."

Thatcher supported Lord Rothschild's 1971 proposal for market forces to affect government funding of research.
Although many scientists opposed the proposal, her research background probably made her sceptical of their claim that outsiders should not interfere with funding.
The department evaluated proposals for more local education authorities to close grammar schools and to adopt comprehensive secondary education.
Although Thatcher was committed to a tiered secondary modern-grammar school system of education and attempted to preserve grammar schools, during her tenure as education secretary she turned down only 326 of 3,612 proposals (roughly 9 per cent) for schools to become comprehensives; the proportion of pupils attending comprehensive schools consequently rose from 32 per cent to 62 per cent.
Nevertheless, she managed to save 94 grammar schools.


During her first months in office she attracted public attention as a consequence of the government's attempts to cut spending.
She gave priority to academic needs in schools, while administering public expenditure cuts on the state education system, resulting in the abolition of free milk for schoolchildren aged seven to eleven.
She held that few children would suffer if schools were charged for milk, but agreed to provide younger children with ⅓ pint daily for nutritional purposes.
She also argued that she was simply carrying on with what the Labour government had started since they had stopped giving free milk to secondary schools.
Milk would still be provided to those children that required it on medical grounds and schools could still sell milk.
The aftermath of the milk row hardened her determination, she told the editor-proprietor Harold Creighton of The Spectator: "Don't underestimate me, I saw how they broke Keith [Joseph], but they won't break me."

Cabinet papers later revealed that she opposed the policy but had been forced into it by the Treasury.
Her decision provoked a storm of protest from Labour and the press, leading to her being notoriously nicknamed "Margaret Thatcher, Milk Snatcher".
She reportedly considered leaving politics in the aftermath and later wrote in her autobiography: "I learned a valuable lesson [from the experience].
I had incurred the maximum of political odium for the minimum of political benefit."
The Conservative Party led by Edward Heath won the 1970 general election, and Thatcher was appointed to the Cabinet as secretary of state for education and science. Thatcher caused controversy when after only a few days in office she withdrew Labour's Circular 10/65 which attempted to force comprehensivisation, without going through a consultation progress.  She was highly criticised for the speed in which she carried this out. Consequently, she drafted her own new policy (Circular 10/70) which ensured that local authorities were not forced to go comprehensive. Her new policy was not meant to stop the development of new comprehensives; she said: "We shall ... expect plans to be based on educational considerations rather than on the comprehensive principle."
Thatcher supported Lord Rothschild's 1971 proposal for market forces to affect government funding of research. Although many scientists opposed the proposal, her research background probably made her sceptical of their claim that outsiders should not interfere with funding. The department evaluated proposals for more local education authorities to close grammar schools and to adopt comprehensive secondary education. Although Thatcher was committed to a tiered secondary modern-grammar school system of education and attempted to preserve grammar schools, during her tenure as education secretary she turned down only 326 of 3,612 proposals (roughly 9 per cent) for schools to become comprehensives; the proportion of pupils attending comprehensive schools consequently rose from 32 per cent to 62 per cent. Nevertheless, she managed to save 94 grammar schools.

During her first months in office she attracted public attention as a consequence of the government's attempts to cut spending. She gave priority to academic needs in schools, while administering public expenditure cuts on the state education system, resulting in the abolition of free milk for schoolchildren aged seven to eleven. She held that few children would suffer if schools were charged for milk, but agreed to provide younger children with ⅓ pint daily for nutritional purposes. She also argued that she was simply carrying on with what the Labour government had started since they had stopped giving free milk to secondary schools. Milk would still be provided to those children that required it on medical grounds and schools could still sell milk. The aftermath of the milk row hardened her determination, she told the editor-proprietor Harold Creighton of The Spectator: "Don't underestimate me, I saw how they broke Keith [Joseph], but they won't break me."
Cabinet papers later revealed that she opposed the policy but had been forced into it by the Treasury. Her decision provoked a storm of protest from Labour and the press, leading to her being notoriously nicknamed "Margaret Thatcher, Milk Snatcher". She reportedly considered leaving politics in the aftermath and later wrote in her autobiography: "I learned a valuable lesson [from the experience]. I had incurred the maximum of political odium for the minimum of political benefit."
Margaret Thatcher