UKIP leader Nigel Farage has accepted a challenge from Nick Clegg to have a public debate on the merits of the UK's membership of the EU.
"I can hardly wait," he told LBC radio, saying the deputy prime minister was "all over the place" on the issue.
He also urged David Cameron and Ed Miliband to take part in a contest ahead of May's European elections.
UKIP, which wants to leave the EU, hopes to top May's poll while the Lib Dems say they are "the party of 'in'".
The Lib Dem leader threw down the gauntlet to Mr Farage on Thursday, saying he was the right person to debate the issue of Europe with the UKIP leader.
In response, Mr Farage said he wanted the Conservative and Labour leaders to join in a four-man debate, which he suggested should take place during the campaign in April or May.
But, even if they declined, he said he would take on the Lib Dem leader in a head-to-head duel, adding "it's on".
He said he had been inspired to enter politics because "we weren't having a proper talk" about the "great question of who governs our country: our own Parliament... or the European Commission and the other institutions in Brussels".
Mr Farage continued: "I've battled on for 20 years, I've been laughed at, ridiculed, attacked. But at no point in the 15 years that I've now been an MEP have we ever had a full national debate about the merits or demerits of EU membership.
"Therefore, when the deputy PM says he wants to go public and have a debate with me on this issue, I have absolutely no choice.
"I've got to say yes, because we need to have a national debate on what I think is the most important issue this country has faced for hundreds of years."
But there was "one small caveat", he added: "I do really want for the Labour Party in the shape of Ed Miliband and the Conservative Party, in the shape of the prime minister, to join this debate as well."
However, he predicted that the two men would decline. "In fact, Downing Street have already briefed that David Cameron was actually too busy running the country" he added.
LBC presenter Nick Ferrari, who hosts regular phone-ins with both Mr Clegg and Mr Farage on the station, suggested that the broadcaster would be keen to host such a debate.
Asked later where it would take place, Mr Farage suggested there could be a "bidding war" among broadcasters.
He also predicted that the debate with Mr Clegg could be a stepping stone towards UKIP's inclusion in TV debates expected to take place during the 2015 general election.
If UKIP topped May's poll, he added, "how can they possibly keep us out of the leaders' debates next year?"
The Lib Dems said they welcomed the prospect of a head-to-head encounter with Mr Farage on Europe, adding that "both sides will now get together to discuss how we can make this happen".
Speaking on Thursday, Mr Clegg said he wanted to make the case for EU membership being vital to the UK's economic prosperity and its security.
"I will challenge Nigel Farage to a public, open debate about whether we should be in or out of the EU, because that is now the choice facing this country and he is the leader of the party of 'out'; I am the leader of the party of 'in'.
"I think it's time we now have a proper, public debate so that the public can listen to the two sides of the argument and judge from themselves."
But Labour appeared to distance itself from the idea.
"The priority for us is to ensure that there are debates agreed between the two prospective prime ministers of the country - Ed Miliband and David Cameron - at the time of the general election," a spokesman said.
"Anything else will be a matter for negotiation after that is agreed."