Nigel Farage has promised to "professionalise" his party, lashing out at the “Walter Mittys” causing embarrassment to UKIP.
The party is set to hold day-long assessment centres to find the best candidates to put forward for next year's general election, following a fresh wave of embarrassing blunders.
The Ukip leader has already vowed to rid the party of those with "extremist, barmy or nasty" views and now he has admitted, again, that in the past his party has "got it wrong" with people who turned out to be "disappointments".
All 1,818 candidates running for the eurosceptic party are being vetted, Farage said, while insisting that "of all the candidates we fielded, only about half a dozen have caused us any embarrassment".
Again emphasising his efforts to streamline his party, the Ukip leader today told The Times newspaper that it's "very natural that a newish party will attract all sorts of people."
Ukip, he said, had not always been successful in screening out the "Walter Mittys seeking a role in politics which, in the end, they will let down not just us but themselves with".
He is referring to the inept protagonist in James Thurber's short story "The Secret Life of Walter Mitty", recently brought to life by Ben Stiller in film that has received less than positive reviews.
Mr Farage said he wanted the party to become more professional and admitted that in its early days Ukip had a "struggle with talent."
Ukip faced more embarrassment this month when a local councillor, David Silvester, said the recent floods had been God's punishment for new gay marriage laws.
The Ukip leader dealt with the media blow by reading out the weather for the Sunday Politics.
Farage, himself last week got into a spot of bother after he insisted it was just "a fact" that women who made the "lifestyle choice" to have children would be paid less.
It also emerged yesterday that one of Ukip's former members, MEP Godfrey Bloom, mocked a disabled student during an Oxford Union debate last week, asking whether he was Richard III, the medieval king who suffered a spine deformity.
Bloom had previously derided Britain's aid to 'Bongo Bongo' land, called a roomful of female supporters 'sluts' at the party conference, and then hit Channel 4's Michael Crick on the head with a rolled up brochure.
Now, Farage has said he has hopes his party will become a "disciplined election machine", and also hinted that candidates would have to curb any eccentric views, saying: "We must together be campaigning on similar issues."
Mr Farage told the newspaper it was "not just about the odd barmy opinion - it's really to try and work out whether these are reliable, steady, solid people."
Looking ahead to the elections, Mr Farage claimed that a third of Ukip's support now came from former Labour voters.
But he risked alienating this new campaigning ground by defending large bonuses for bankers, saying: "The very thought that the bureaucrats in Brussels now set the limits we can pay the highest earning people in London is truly astonishing."
But he attacked the pay of some in local government and non-governmental organisations, saying it was a bigger issue than the pay of bankers.