The UK Independence Party says it will "completely change British politics" if it wins in European elections next year.
Head of policy Tim Aker told the BBC that UKIP is attracting former non-voters, people who have ''given up on the other parties".
The party, which wants tighter controls on immigration and advocates Britain leaving the European Union, came second at the last European elections in 2009.
It was "absolutely" sure of a triumph next time around, Mr Aker said.
The BBC reports UKIP has seen its poll ratings improve markedly over the last few years and won more than 140 seats in council elections in May.