Ukip leader Nigel Farage insisted the party could win votes from across the political spectrum as he rallied activists on Saturday.
Speaking at the party's spring conference in Exeter, Farage said there was a "wholesale rejection of the career political class going on".
But he argued that Ukip's recent second place in the Eastleigh by-election - knocking the Tories into third - was about more than protest votes.
In a swipe at David Cameron, Nick Clegg and Ed Miliband, Farage said the public was tired of people who viewed politics as a profession.
"We have really had enough of them," he said. "They really do all look the same... they all go to the same schools, the same Oxbridge colleges.
"None of them has ever had a job in the real world and not one of them is in politics for principle. That is what we stand for."