Top politician claims an Aussie prime minister hit Margaret Thatcher with X-rated verbal slurs over one of rugby's most controversial issues

A former Australian government minister has claimed late PM Bob Hawke verbally abused his UK counterpart Margaret Thatcher over the British Lions' plans to tour South Africa while the country was still in the grip of apartheid.

John Brown, who was the Minister for Sport, Recreation and Tourism in Hawke's government from 1984 to 1987, made the stunning assertion as he launched his autobiography in Sydney this week.

Britain's rugby side had planned to play in South Africa in 1986, but the tour was cancelled at a time when the nation was a sporting outcast due to the brutally racist regime.

Brown told the crowd at the launch of his book that he arranged for Hawke to speak to Thatcher about the tour before it was axed.

The late PM was worried about the tour's potential to disrupt the 1986 Commonwealth Games should it have gone ahead, with many African nations boycotting the event over the refusal of UK sporting bodies to cut ties with South Africa.

Brown claimed the Australian leader lost his cool during the phone call and told Thatcher: 'Listen, you f***ing b***h, get that f***ing team to withdraw from South Africa or otherwise the Commonwealth Games will implode and possibly the Commonwealth of Nations.

'You are the f***ing Prime Minister of England and the future of both is in your hands.'

According to Brown's account, which was relayed by the Sydney Morning Herald, Thatcher then agreed to halt the tour.

However, at the time it was reported that the South African Rugby Board called off the matches partly due to the fact the country was in a state of emergency for much of that year.

Hawke was a huge opponent of apartheid and credited himself with coming up with the 'dagger' that helped kill off the racist system.

'Trade sanctions weren't working so I had this concept that if we could boycott foreign investment in South Africa we could bring it to an end,' he said in 2016, three years before his death.

'My fellow leaders of the Commonwealth supported my concept and in a very short time it worked.

'The investment boycott was the dagger which finally immobilised apartheid.'

In contrast to Britain, Australian rugby teams refused to play against apartheid South Africa after hosting the Springboks in 1971, when the tour resulted in protests around the country.

While Britain's mooted tour of South Africa was called off in 1985, the Lions did play an international side featuring Springboks stars in Wales in April 1986 to celebrate the centenary of the International Rugby Football Board.

Hawke and Thatcher's thorny relationship was laid bare in British cabinet papers that came to light in 2014.

They showed that Britain's Foreign Office described Hawke to Thatcher as 'often deliberately abrasive and even arrogant' and warned he had 'a widely known weakness for drink and women'.

Hawke described their differences over South Africa soon after the release of the papers.

'We agreed on many things but our big point of difference was the apartheid regime in South Africa,' Hawke explained.

'I led the fight in the Commonwealth against that, trying to smash it, which we would finally be successful in doing, but Margaret would never join that fight and so I had some famous stoushes with her.'