The founder and former leader of Ukip, Professor Alan Sked, says the party he launched in 1993 has become a "racist political failure" led by someone who "isn't bright."
In an astonishing tirade against the Eurosceptic party and Nigel Fraage, Sked said Ukip's MEPs do "fuck all" – except to take taxpayers money.
"They're no better than these people on [Channel 4 documentary series] Benefits Street," he said. "Farage has become a millionaire from expenses."
In a lengthy interview with The Guardian, Sked enthusiastically dismisses Farage's claims that he is on the path to Westminster.
"He's a fantasist. They always do well in Euro elections because they're the obvious party of protest, but the idea that they're going to come from nothing to be holding the balance of power is ridiculous. I don't expect them to get any seats," he said.
Any vote for Ukip in the European poll, Sked said, was wasted. "There's no reason to vote for Ukip," says Sked, "because if they believed in what they said they wouldn't be there."
"If you elect a Ukip MEP, you're just going to elect another incompetent charlatan that you're going to turn into another millionaire. They go native in Brussels, take the expenses and the perks and do fuck all."
Ukip was revealed as the laziest party in the whole of Europe this month, missing more than one in three votes in Brussels.
Farage’s MEPs turned up for just 61.1% of votes, putting them at the bottom of a league table of 76 parties from across the whole of the EU.
"The party I founded has become a Frankenstein's monster," Sked sighed.
But as a triumphant Farage, 50, heads out on the victory trail following his party's historic success in the European Elections, he has declared "you ain't seen nothing yet."
Sked is not so convinced, describing the Ukip leader as "swallowing his own propaganda."
"He's been de facto leader of the party since 1999 and he hasn't won a single seat [at Westminster]," says Sked. "How he thinks he's going to get the balance of power I don't know.
Sked, who infamously fell out with Farage and has admitted to trying to oust the Ukip leader, goes on to argue it's simply because Farage is not a very intelligent person.
He recalled: "I spent two hours trying to explain to him the difference between 'it's' with an apostrophe and 'its' without and he just flounced out the office saying, 'I just don't understand words.'"
The comments came as Farage's wife today described how her husband is totally incompetent with computers despite living in an age where they are arguably quite important.
She described how Farage has a "steam-powered telephone, he can send and receive texts and that's it. If I sit him down, and there is something for him to read, he can scroll up and down, he has learned that - but that is pretty much it.
"He honestly doesn't know how to [use a computer] and he has missed the boat, I don't think he ever will now."
Sked recalls, too, letters of complaints he received when Farage stood for Ukip in 1997's general election. "I remember one that said, 'I'm very glad your candidate believes in education, but until he learns to spell it, I'm not voting for him.' That's the kind of person people are voting for when they vote Ukip. Why does anyone have time for this creature? He's a dimwitted racist."
So is Ukip now a racist party? Oh yes, argues Sked.
Reviving claims that Farage repeatedly used the n-word when referring to black voters, Sked described: "He wanted ex-National Front candidates to run and I said, 'I'm not sure about that,' and he said, 'There's no need to worry about the nigger vote. The nig-nogs will never vote for us.'"
Farage has denied that he said these words and always insists that he is not racist.