Stuart Wheeler, the Kent-based spread-betting millionaire tycoon expelled from the Conservatives, will now campaign for the United Kingdom Independence Party, says its leader.

Nigel Farage, UKIP leader, said he expected Stuart Wheeler, who owns Chilham Castle, near Canterbury to fight for the Euro-sceptic party on the campaign trail ahead of the June election.

Mr Wheeler has already said he will vote for UKIP in the European elections. It follows his expulsion from the Conservative party after his decision to donate £100,000 to UKIP.

But Mr Farage said he now expected Mr Wheeler to take a more active role.

"I think the intolerance that has been shown to Mr Wheeler means that he will fight as hard as he can for UKIP. We will be asking him to appear for us in the press and on TV and radio because he believes in what he is doing very passionately," said Mr Farage.

But he ruled out the idea that Mr Wheeler could become a candidate for UKIP. "He's not expressed an interest in that but he has made a welcome contribution and I am very happy with that."

He urged Conservative supporters to switch their votes to UKIP at the European elections, saying it was a chance for them to indicate what kind of future Conservative government they wanted.

"Given the likelihood the Labour vote will collapse, the question that the Conservative supporters will have to ask is what kind of Conservative government they want? By voting UKIP, they can send an important message."

Mr Wheeler said: "[UKIP's] position is far nearer to what I would like to happen than anybody else's.

"I do want the Conservatives, if they are in power, to try very hard to get the European Union to accept a much looser relationship and to put us back into a position more or less where we were when we first joined - a wonderful trading relationship, but not much else."

Mr Wheeler has made major donations to the Conservative party over the years.