The man who founded Ukip has claimed that the eurosceptic party he set up 20 years ago has become “anti-immigrant, anti-intellectual and racist”.
Professor Alan Sked has also revealed he once expelled current party leader Nigel Farage.
The historian launched Ukip in September 1993 and it is now widely considered to be a growing force in British politics, after winning 23 per cent of the vote in last month’s local elections in England. Ukip came second in three recent by-elections.
Many Conservative MPs fear Mr Farage’s party could split the right-wing vote at the next election and cost David Cameron a majority in 2015’s UK general election.
Prof Sked, who is based at the London School of Economics, said he is “delighted” that the Conservatives are being put under pressure over Europe.
However, he added: “My great regret is that the party I founded has been captured by the radical right and has gone all anti-intellectual. It’s gone completely fruitcake.”
Mr Farage’s recent attempt to stage a press conference in Edinburgh was hijacked by pro-independence campaigners urging him to return to England.
He attacked the “racist” extremes of Scottish nationalism.
Mr Farage denied that his party was racist or anti-immigrant.