Almost two decades after she ended free school milk Margaret Thatcher still recoiled at memory of the political storm she unleashed, newly released government files reveal.

As Education Secretary in Edward Heath’s government her decision in 1971 to stop the provision of milk for junior school pupils prompted the playground taunt “Thatcher, Thatcher, milk snatcher”.

Files released by the National Archives show that 19 years later, Thatcher – by then Prime Minister – was horrified when Health Secretary Ken Clarke proposed finally ending free milk for nursery schoolchildren as well.

“No – this will cause a terrible row – all for £4m. I know – I went through it 19 years ago,” she scrawled in a handwritten note.

“Health has enough to do to get the white paper and community proposals through. Any scheme for saving £400m or more I will look at. But not £4m.”

Thatcher was also appalled when, six years after the Falklands War, Foreign Secretary Sir Geoffrey Howe suggested he should make a courtesy call on the Argentinian foreign minister, who had just been elected President of the United Nations General Assembly.

“I utterly recoil from this, and so I think would the relatives of all those who lost their lives in the Falklands. Argentina has not announced a cessation of hostilities,” she wrote.