There is a massive appetite out there for change." Mr
Farage's party has made inroads in Labour's northern strongholds in recent elections, and he said: "We're going all out for the workingclass vote now.
Mr Farage said the party was "testing the waters" with potential turncoats - both Tory and Labour - and predicted Ukip could hold the balance of power in the next Parliament.
With the Westminster rumour mill on full throttle, Tory MP Zac Goldsmith yesterday denied he would be joining fellow Tory Douglas Carswell by jumping ship to the anti-Brussels party.
It came as a dramatic new poll gave Ukip a massive 44-point lead over David Cameron's party - and Mr Farage predicted that a win would result in "more and more people coming over to us".
The Clacton poll put Ukip on 64 per cent, the Tories on 20, Labour on 13 and the Lib Dems on 2. More than half favoured quitting the European Union, with 54 per cent supporting a British exit and 26 per cent opposed to cutting ties to Brussels.
In a sign of Mr Carswell's popularity in the seat, 34 per cent of those indicating they would vote Ukip said it was because they liked their former Conservative MP.
Fifty seven per cent said it was because they liked Ukip and nine per cent said it would be a protest vote.
Among Tory voters, 49 per cent said Mr Carswell was a hero despite his defection, with just 17 per cent saying he was a traitor.
Mr Farage said the stakes were high in the contest for the Essex seat, which will see Mr Carswell take on his former party.
The Ukip leader added: "This is the moment. If we win the by-election in Clacton, it will create a landslide in British politics.
"If we lose, then selling ourselves as a party that can win a significant number of seats will get a lot harder.
"If Douglas wins this by-election, then there will be more and more people coming over to us. We could end up holding the balance of power by next May."
He added: "I'm going to keep playing double or quits until I lose.
"But if I win three more hands, we'll be out of the EU and a free country again. There is a massive appetite out there for change." Mr Farage's party has made inroads in Labour's northern strongholds in recent elections, and he said: "We're going all out for the workingclass vote now. Five of our most winnable seats are Labour-held and there are even some Labour MPs thinking of joining us."
Mr Cameron has dismissed Mr Carswell's decision as "bizarre" because he had promised a referendum on the UK's membership of the EU by the end of 2017.
Mr Goldsmith took to Twitter yesterday to dispel newspaper suggestions he was going to defect if the Government changes its stance on green subjects.
"I was critiquing Ukip's position on green issues to illustrate why I couldn't join them," he said.
Tory MP Nigel Evans said: "I fought the Ribble Valley by-election in '91. It was the 13th safest seat in the land and we lost it and a year later I was the MP. So how important are these by-elections?"