In the BBC television archives on militant anti-apartheid protests in 1969-70 against the touring all-white Springboks, there is a familiar figure to me and a generation of labour movement activists.

Bill Laithwaite, a balding, bespectacled pensioner, is seen being wrestled off the pitch by two police officers at Twickenham, blood seeping from a small wound on his face, having hoodwinked his way into the playing area by dressing like a match official.

Laithwaite was a member of the Communist Party and active in the Stop the Seventy Tour campaign, of which I was chairman.

That match, the first during the rugby tour, saw pitch invasions and constant hostile chanting.

For the first time the Springboks, accustomed to being lionised as perhaps representing the leading rugby nation in the world, had instead been treated as pariahs.

They were no longer faced merely with what they habitually dismissed as the spluttering of "misguided liberals and leftists" holding placards outside rugby stadiums while they retreated into the warm hospitality of their hosts.

This was something of quite a different order. Anti-apartheid opponents had now shown a physical capacity to threaten the Springboks' ability to tour in the old way.

Around 100,000 protesters laid siege to the white South Africans during their 25 matches across Britain and Ireland, providing a perfect springboard from which to plan direct action to stop the cricket tour due to begin in May 1970.

An Anti-Apartheid Movement poster caught the public's imagination and was widely published in the press.

Under the caption: "If you could see their national sport you might be less keen to see their cricket," it showed a policeman beating defenceless blacks in Cato Manor township outside Durban.

After months of mounting pressure to wreck the cricket tour, cricket bosses were finally forced to do the previously unthinkable. It was cancelled.

Soon white South Africa was propelled into sporting isolation, banned from competing internationally in rugby, cricket, football, the Olympics and all sports.

Long used to evading economic and arms sanctions with the assistance of Western countries like Britain, on sport, so vital to their psyche, they had been beaten.

For the first time in 10 long bitter years since the 1960 Sharpeville massacre the anti-apartheid resistance had something to cheer about.

In that period the apartheid state seemed omnipotent. Western countries were investing in and trading with South Africa and also supplying arms.

MI5 and MI6 with the CIA were allies of the notorious apartheid secret service BOSS. Nelson Mandela was then imprisoned with the rest of the resistance leadership, the ANC having been banned and forced into exile or underground.

After their release 20 long years later, both Mandela and his comrade Govan Mbeki told me that on Robben Island information on the demonstrations slipping through the news blackout had given all the political prisoners there an enormous morale boost.

Moses Garoeb, a leading freedom fighter in the South West African People's Organisation, also told me in the early 1970s that the Stop The Tour success had been an "inspiration" to Swapo cadres in the Namibian bush as they heard the news on their radios.

Almost every time we subsequently met, Mandela never failed to mention how indebted he was to international anti-apartheid activists. And, although he is now hailed as an almost saintly, universal hero - even by the Conservatives - we should remember our history.

The British right was on the side of pro-apartheid forces. The struggle was won despite them, by resistance inside South Africa and solidarity work outside.

It was people like Laithwaite - and Ethel de Keyser and Mike Terry, the indefatigable executive secretaries of the anti-apartheid movement - who helped win it.

The Stop the Tour movement was opposed by Tories, fascists and racists.

Against them it had broad support from trade unionists, students, Christian groups, bishops, communists, Trotskyists, Labour Party members and liberals.

British trade union leaders including Lawrence Daly, Ken Gill, Ron Todd, Rodney Bickerstaffe and Jimmy Knapp gave leadership and solidarity. So did Labour MPs like Michael Foot, Neil Kinnock, Richard Caborn and Bob Hughes.

By contrast, some Tory MPs became known as "members for Pretoria."

One was even involved in a private prosecution against me for conspiracy to stop the tours, nearly having me jailed after a month-long Old Bailey trial in 1972.

Conservative Students wore Hang Nelson Mandela badges and Margaret Thatcher denounced him as "a terrorist."

"Forgive," urged Mandela after the battle against apartheid triumphed, "but never forget."

Labour MP Peter Hain's memoir Outside In is published by Biteback and his biography Mandela by Spruce. Both are also available in eBook.