One of the British National party's first MEPs' attempts to play down his past links to the extreme right as "silly" teenage posturing are today exposed as a sham after it emerged that for many years he played a crucial role in shaping the National Front's most overtly racist policies.

In 1983, when he was in his late twenties, Andrew Brons edited the National Front's general election manifesto that called for a global apartheid to prevent the "extinction" of whites everywhere.

The Let Britain Live! manifesto was prepared by the party's policy department, chaired by Brons. It outlined a series of hugely controversial positions, crystallised in one of its opening statements: "The National Front rejects the whole concept of multiracialism. We recognise inherent racial differences in Man. The races of Man are profoundly unequal in their characteristics, potential and abilities."

The manifesto claimed the UK had been "swamped" by "racially incompatible Afro-Asians" and that "Black muggings of White people, especially elderly ladies, occurs regularly".

It continued: "The eruptions in Bristol in 1980 and Brixton in 1981 were just two examples of the 'cultural enrichment' promised to us by the multiracialists." And it claimed: "We believe the gradual dismantlement of the Apartheid system over the last 17 years to be retrograde ... The alternative to Apartheid, multiracialism, envisages an extinction of the White man."

Brons was also an enthusiastic contributor in the 1970s and 1980s to Spearhead, a far-right magazine considered so extreme even the BNP tried to distance itself from it. In two lengthy polemics for the magazine, Brons outlined the supposed importance of nationalism and interpreted genetic studies to suggest Europeans had a "greater cognitive ability" than non-whites. He attacked the influence of "people of Jewish ethnic origin" and peddled the myth that a number of predominantly Zionist organisations were controlling the world.

The now retired college lecturer wrote: "One ethnic, national and religious group whose power and influence has undoubtedly increased has been the Jews. It can be no mere coincidence that the number of people of Jewish ethnic origin to be found in internationalist and multiracialist schools of thought and organisations of action is out of all proportion to their numbers in the population."

Brons, who was elected as the BNP MEP for Yorkshire and the Humber this month, has tried to distance himself from his National Front days. "People do silly things when they are 17," he said recently. "Peter Mandelson was once a member of the Young Communist League but we don't continue to call him a communist."

But his critics say his relationship with the National Front was more than a youthful dalliance and question the extent to which he has left his past behind. A 1980 edition of National Front News, the party newspaper, carried an article about Brons saying he was prepared to go to jail for his beliefs. It noted that Brons refused a "Negro reporter permission to attend two National Front ticket-only meetings" and explains that Brons, then 29, has "campaigned against Coloured Immigration since he was a teenager" - suggesting his extremist views have been a feature as much of his adult as his teenage life.

Brons seized the NF chairmanship in 1980 when John Tyndall quit to form the BNP. In 1984 Brons was convicted of using insulting behaviour towards an ethnic-minority police officer and left the party, citing family problems.

At the National Front, Brons was a close ally of Richard Verrall, the author of the Holocaust-denial tract Did Six Million Really Die?, who was vice-chairman. In 1981, while Brons was chairman, the NF endorsed We are National Front, a pamphlet carrying an introduction from Verrall. It had photographs of Brons and Verrall as well as a picture of a gorilla and a black man stating: "These two creatures look the same, don't they?"

Anti-racism and Jewish support groups yesterday described Brons's failure to condemn his past activities as disturbing. "From a young man until well into his middle age, Andrew Brons was very much involved in a series of viciously antisemitic and racist far-right movements," said a spokesman for the Community Security Trust, which monitors attacks on the UK's Jewish community. "It's hard to believe he has undergone a serious conversion since then."

Searchlight, the anti-fascist organisation, said Brons was influential in shaping the NF and it was important that those voting for him should be aware of his past views. "The fact that Brons is an intellectual fascist and bigot rather than an ignorant fascist and bigot cuts little ice," a spokesman said. "We are unimpressed by his claims that his prejudice was a result of youthful exuberance."

Attempts to contact Brons through the BNP were unsuccessful.