David Cameron acknowledged that the Tories had a fight on their hands in the General Election as he prepared for the second crucial televised leaders' debate.
The Conservative leader is under pressure to put in an improved performance after he was outshone by Liberal Democrat chief Nick Clegg in the first 90-minute encounter.
With the Lib Dems still riding high in the opinion polls after last week's head-to-head, Foreign Secretary David Miliband said that Mr Cameron now needed to deliver a "knockout" blow to his rival.
The Lib Dem resurgence threatens to derail Mr Cameron's hopes of reaching No 10 with an outright majority.
The Tory leader insisted that he was trying to ignore the "hype" surrounding the debate - to be hosted by Sky News in front of a studio audience in Bristol - and just "do what you normally do".
"We've got a fight on our hands. There's no doubt about it," he told reporters, after jogging in Exeter.
"These debates are big events and we've got to do everything we can to explain to people, particularly back home sat watching the TV, why we would make a difference, what we are about, how we would change the country. People are really depressed with politics at the moment and they need to be inspired."
However, Mr Miliband sought to pile the pressure on Mr Cameron, insisting that he needed to do better after having been "exposed" in the first debate.
"The style debate between David Cameron and Nick Clegg will carry on. David Cameron obviously needs to deliver a knockout to Nick Clegg," he told GMTV.
He acknowledged that Gordon Brown could not compete with his younger rivals on presentation, but said that he believed that the Prime Minister's strengths would come through as voters focused on the issues. He said: "Gordon is the only man standing on that stage with the strength and the clarity to govern the country. Because opposition is about protest but the government is about tough decisions and the right decisions."