Speaking at the party conference in Exeter, Nigel Farage said UKIP is moving past being a protest group, the Evening Standard reported. He said recent polls and by-election results show a "wholesale rejection of the political class."
"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."
While UKIP, founded in the 1990s, has yet to win a seat in the House of Commons, it holds 11 seats in the European Parliament. Its candidates have come in second in some recent by-elections, and recent polls have suggested it now has more support than the Liberal Democrats, the Conservatives' ally in the governing coalition.
In the recent Eastleigh by-election to replace the disgraced former Liberal Democratic Cabinet minister Chris Huhne, UKIP ran ahead of the Conservative and Labor parties and less than 5 percentage points behind the Lib Dems, who retained the seat.
Farage, a former Conservative, said the party will gain support from left, right and center.
"It is something far more powerful than a protest vote," he said. "Actually the vast majority of the people going out and voting UKIP in these by-elections do so because we are the people that are putting forward positive alternative policies that would make this country a better and prouder place."