Former Tory prime minister Margaret Thatcher was on the wrong side of history when she opposed strong sporting sanctions against South Africa's apartheid regime, her successor Sir John Major has said.

He spoke out amid claims from the likes of veteran anti-apartheid campaigner Peter Hain that the Tories were attempting to rewrite their history over support for Nelson Mandela.

Major was among the group of former premiers to attend the tributes to Mandela. When asked if Thatcher had been on the wrong side of history, he said: "Absolutely she was. We should have realised what was happening earlier."

His remarks echo those of current Tory prime minister David Cameron who, on a visit to South Africa in 2006 told Mandela: "The mistakes my party made in the past with respect to relations with the ANC and sanctions on South Africa make it all the more important to listen now."

That was seen as acceptance that the Conservatives had got it wrong over apartheid throughout the period, but Cameron has stopped short of being more direct or apologising.

There has been much controversy over Thatcher's role in opposing sanctions, with her supporters insisting she pressed the South African regime hard to release Mandela but worried sanctions would only hurt the black population.

Former Tory ministers, including Lord Tebbit, have suggested it was her influence through engagement with the regime that actually helped bring about Mandela's release.

But that notion has been flatly dismissed by those close to Mandela, including Hain who said the man himself did not believe that to have been the case.

He accused the Thatcher government of displaying "craven indulgence" of apartheid and the Tories of attempting to re-write their past record on the issue.

Throughout the period she described the African National Congress as a terrorist organisation and banned ministers from talking directly to it.

And observers at the time were in no doubt that the Tory government was no supporter of Mandela's or the ANC and some MPs were even openly supportive of the apartheid regime.