When on Thursday night this blog put up a picture of Margaret Thatcher and Nelson Mandela together the abuse on Twitter from some quarters was more self righteous than Guido can recall ever before. It was also wrong.

The myth that Thatcher (and her admirers) supported apartheid is one of the core beliefs of the Comrade Blimpish left. Charles Moore touched on it in The Telegraph this morning. It is a false charge and Nelson Mandela himself was in no doubt – saying of Margaret Thatcher in July 1990 only a few months after his release: “She is an enemy of apartheid… We have much to thank her for.”

Mandela knew that for years behind the scenes she had been arguing with the South African apartheid regime for his release. Written evidence of her lobbying only came to light decades later when the ANC government released a now declassified secret 1985 letter from Margaret Thatcher to P. W. Botha. Comrade Blimp-types just won’t accept the fact that she did more to encourage the end of apartheid than Paul Weller and Billy Bragg. They’re wrong.

Read the entire letter here