Cameron tells UKIP voters only Tories can deliver
David Cameron has made a direct appeal to UKIP voters, saying Britain needs the "politics of the answer rather than the politics of anger".
He said UKIP presented a "totally unrealistic, pessimistic vision about what this country can achieve".
He told the BBC's Nick Robinson he understood people's anger about immigration and the EU, but only the Tories had the answers.
UKIP said the PM lacked the courage to debate his views with Nigel Farage.
In an interview with the BBC's political editor Mr Cameron said: "My appeal to people is actually vote for a party that can deliver, that can get things done
"I understand the things that you find frustrating, the things that you care about.
"We are delivering. Don't waste your vote on a party that can't deliver."
He said UKIP "may come up with phrases or expressions that attract you on some of these issues but they can't actually deliver the answers".
The prime minister was speaking ahead of 22 May's local and European elections.
The prime minister also defended his plan for a referendum on Britain's membership of the European Union in 2017 and insisted that it would not guarantee that another government led by him would be "obsessed by Europe divided and distracted from the concerns of ordinary people".
He claimed that business backed his plan to re-negotiate Britain's relations with Europe and then put that to the people.
Mr Cameron said that over the next three years the country had three fundamental choices to make - whether to break up the UK, whether to back his long-term economic plan and whether to stay in a reformed EU.
He said he hoped to convince people to back his plan for the UK but said he knew he might be packing his bags and moving out of Number 10 this time next year.
"I understand that the people are the boss at the end of those 364 days - it's called democracy. It can be painful but it's a very good thing."
A UKIP spokesman said: "All David Cameron has delivered on the EU is open-door immigration from Romania and Bulgaria and higher British budget contributions.
"Mr Cameron seems to have strong opinions to share about UKIP, but also to lack the courage to test them in debate against Nigel Farage.
"His performance is lamentable and widely seen as such."