Cameron: I’ll quit if I don’t get EU referendum

The prime minister said he was confident he would be able to renegotiate the terms of UK membership, including securing reform of the rules on border controls and benefits.

Mr Cameron said the “most important” change would be to get Britain out of a clause committing it to an ever closer union.

Speaking on the BBC’s Andrew Marr Show, he said: “I’ve said very clearly that whatever the outcome of the next election, and of course I want an overall majority and I’m hoping and believing I can win an overall majority, but people should be in no doubt I will not become prime minister unless I can guarantee that we will hold that referendum.

“I won’t become prime minister unless I can guarantee that that in/out referendum will be held.”

He added: “We have the referendum whether or not I have successfully negotiated.

“Now, I believe I will be successful and for a couple of very good reasons. First of all, others in Europe need change to the European Union, the eurozone, the euro currency, needs change because it needs a banking union, it needs more fiscal union and so we are perfectly legitimate to ask for our changes.”

Mr Cameron wants to renegotiate powers over border control, crack down on benefit tourism, secure more trade and have greater control over justice and home affairs.

He told the programme: “I would like to see longer periods in terms of before you are allowed to claim any benefits.

“Let’s look at what is possible but certainly what is longer than what we have today.”

The prime minister said free movement within the EU is “important” but insisted it “needs to be returned to the original concept, which was the freedom to be able to go and work in another country”.

He urged voters not to back Ukip in the forthcoming European elections, saying: “What we need in Europe is a strong Conservative prime minister, backed by a team of strong Conservative MEPs that then will be taken seriously by our European partners.

“The problem with sending Labour and Liberal Democrat MEPs is that they don’t want any change.

“The problem with sending Ukip MEPs is they often don’t turn up, they then vote the wrong way on things like the budget, and they are not taken seriously by other countries and the European Commission.”