In an interview with the Express & Star, Tim Aker said he expected the party to win three of the seven West Midlands seats in the European Parliament in the elections in May.
And he is expecting that the eurosceptics will also become the 'senior opposition' on Dudley Council, replacing the Conservatives.
He defended party leader Nigel Farage, who denounced UKIP's 2010 election manifesto as '486 pages of quasi-academic ramblings and random thoughts which should never have been put near a UKIP logo'.
Mr Aker said: "The old manifesto died after the last General Election. You don't get journalists asking David Cameron about the Tories planning to privatise the London Underground in 1997. We've always believed in leaving the European Union. That has not changed. The previous head of policy put together a manifesto that was almost 500 pages of junk."
But UKIP has been under intense scrutiny, particularly since its success in last year's county council elections.
One of its members, Oxfordshire councillor David Silvester, was suspended after he continued to give media interviews following his claims that recent flooding was punishment for the Tories bringing in gay marriage, the reason he defected from the party to UKIP. Eric Kitson, who was elected to represent Stourport on Worcestershire County Council, stood down after just 13 days after it emerged he had been posting racist and offensive comments on Facebook.
Asked if UKIP had managed to stop any members from causing further embarrassment, Mr Aker said: "We're getting there.
"We have a very thorough scrutiny process. But the Tories have full-time staff going through the Facebook and Twitter of our candidates.
"It's a dirty tricks campaign from the Conservatives."
And Mr Aker said the party was getting more exposure, amid concerns that its only well known names were either Mr Farage or mavericks like Godfrey Bloom, who was stripped of the party whip after comments about 'sluts'.