UK Independence Party leader Nigel Farage has told the party's annual conference that it speaks for the majority of British people.
"I'd call us the commonsense party," he told members in Telford, Shropshire.
"I would say that in terms of the political spectrum and where you should place UKIP, we are at the centre-ground of British public opinion."
Mr Farage, elected leader last month, earlier told BBC Five Live that UKIP was the "real voice of opposition".
'Not given a choice'
Mr Farage told the conference: "They want to know not just what UKIP is against, they want to know what UKIP is for... our job is to present to the electorate a blueprint for how an independent Britain would be governed."
Mr Farage told the BBC: "We've got three social democratic parties in Britain - Labour, Lib Dem and Conservative are virtually indistinguishable from each other on nearly all the main issues," he said.
"Frankly, you can't put a cigarette paper between them and that is why there are nine million people who don't vote now in general elections that did back in 1992."
He said that "a lot of people... feel like me that we're not being given a choice, we're being given no opportunity, that there is no real voice of opposition in British politics - that is what UKIP is here to provide".
Mr Farage had been expected to launch a bid to win over Conservative voters who may be put off by leader David Cameron's move to the centre ground.
UKIP's best known policy is a pledge to withdraw the UK from the European Union if it is elected into power.
But Mr Farage has pledged to end its image as a single issue pressure group.
UKIP is promising a flat rate of tax of 33% - which would make three-quarters of British voters better off, according to Mr Farage.
They are also promising border controls against immigration.
Mr Farage told the BBC that UKIP will also be campaigning for "a proper selective education policy".
The party has never had a candidate elected to the House of Commons, but gained 12 Euro MPs when it finished third in 2004's European Parliament elections, with 16% of all votes.
UKIP did not do as well as it had hoped at last year's general election, losing its deposit in more than 450 seats, but it has come third in two recent Westminster by-elections.