NIGEL Farage insisted his "dream has become a reality" after Ukip redrew the British political landscape by topping the European parliament polls.
Mr Farage said he was convinced his party would kick on from its stunning success - the first time in more than a century that a national vote has not been won by Labour or the Tories - to secure Westminster seats next year.
He also predicted that Nick Clegg would be ejected as Liberal Democrat leader after a disastrous performance that saw the party lose 11 out of 12 MEPs, even forfeiting its deposit in Wales.
"My dream has become a reality," Mr Farage told the BBC. "The British people have stood firm, they have backed Ukip and we have won a national election."
After ten of Great Britain's 11 regional constituencies had declared their results, Ukip had 23 MEPs and a 29.07% share of the vote - up 11.68% on 2009.
Labour had 18 MEPs and a 25.35% vote share, the Tories had 18 MEPs and a 24.56% vote share, the Greens three MEPs and a 7.85% share while the Lib Dems managed a solitary MEP and 6.85% of the vote.
The final result in Scotland will be announced later, but with only the Western Isles left to declare it appears the SNP and Labour will retain their two Scottish MEPs, with the Scottish Tories also keeping their European representative.
Mr Farage repeated his view that Ukip was now the "third force" in British politics, and pledged to sharpen up the party machine over the coming months so it could deal with the "onslaught" from opponents.
Asked if he thought all the main party leaders would still be in place for next May's general election, he said: "They will have changed. I have no doubt about that.
"The leadership of the Lib Dems will have changed."
Mr Farage argued that the Deputy Prime Minister was in an "untenable" position after choosing to take him on in head-to-head debates.
"He put his entire reputation and that of the Lib Dems on those debates, on this election campaign. It would hardly have gone worse for him," he said.
"The Liberal Democrats, they got rid of Charles Kennedy, they got rid of Ming Campbell, they have shown themselves to be pretty ruthless. Actually I think his position as leader of the Lib Dems is pretty untenable."
Mr Farage said Ed Miliband was also facing "very serious" questions after Ukip "dug deep" into the traditional Labour vote.
Despite a strong showing in London, scraping into second place and failing to break through in key battlegrounds has worried some in the party.
If Mr Miliband kept refusing to guarantee the British people a referendum on EU membership he would become the "biggest recruiting sergeant" for Ukip, Mr Farage said.
"I have been looking at some of the constituencies, seats in which we have won council seats, seats in which we have topped the poll. It's clear now that we have a targeting strategy that is valid... Ukip is going to win seats in Westminster next year," he added.
"Everyone keeps saying its the high tide mark for Ukip. I think the party has got real momentum behind it."
Mr Farage also poured cold water on the prospect of an electoral pact with the Tories while David Cameron is in charge of the party.
"They absolutely despise us. In policy terms, we're completely different. I do not think that under David Cameron's leadership that he will allow any kind of joint ticket at the next election," he said.