David Cameron has said the Tories can win the next election, but admitted they had a "huge mountain to climb".
Mr Cameron said the Tories were the "new force" in politics
Days before his first anniversary as Conservative leader, he told ITV 1's Sunday Edition: "We can do it."
"Labour's majority was made in one election, it's much smaller than it was, it can be un-made," he said.
Meanwhile US pollster Frank Luntz has warned Mr Cameron that while floating voters were attracted to his message, he needed to be "a leader not a brand".
Conducting a focus group for the Daily Telegraph, Mr Luntz found that Mr Cameron's strongest criticism, came from fellow Conservatives.
But Mr Cameron said he would not stop trying to reclaim the political centre ground, despite opposition from some Tory traditionalists.
"Yes, I get attacked by newspapers who'd like me to just bring out all the old policies," he said.
"But I haven't wavered one inch from the strategy that I said was the right thing for our party and also the right thing for our country."
He defended his speech calling for more understanding of why young people commit crime - dubbed the "hug a hoodie" speech by his opponents.
And he said he would not come up with policies "for a newspaper headline".
"I think people in this country are crying out for change and for a party that can take us in a new direction," he said.
"I think the Conservative Party is the new force in British politics with the changes that we've made. We're leading the debate but there's a lot more to come."
He also called for reform of party funding to prevent huge loans from private backers.
"I think we have to have a reform that goes right across the piece - and that means all loans should be proper bank loans," Mr Cameron said.
"I think we should have a limit on the amount that people and trade unions and businesses can give to parties."