“The referendum must take place before the end of 2017. If we could do that earlier, I’d be delighted, if we could deliver on this referendum then the sooner I can deliver on it the better,” he told the BBC in an interview.

The conservative leader wants to renegotiate the terms of the UK’s membership in the EU in order to take back some decision-making powers from Brussels.

Ideas include putting unemployment benefit restrictions on EU nationals in Britain looking for work.

“If they don’t have a job within six months they have to go home; they have to work for four years before they can claim things like tax credits,” said Cameron.

He noted the proposals would require a “treaty change, and proper, full-on treaty change.”

Cameron has previously said that reducing the number of EU migrants entering the UK as well as access to the welfare system would be pivotal to the membership talks.

A plan to cap the number EU nationals able to come to the UK was also dropped after provoking a backlash on the principles of free movement from German chancellor Angela Merkel.

It follows a series of other proposals and policy ideas over the last year on stemming immigration, tightening border controls, and imposing benefit restrictions on EU nationals seeking work in the UK.

The highly politicised issues are taking centre stage in the UK debate ahead of the May election as the Conservatives seek to win back voters from Nigel Farage's populist Ukip party.

Cameron is hoping to secure a majority government but has left the door open for a possible coalition with Farage’s Ukip.

The conservative duo both want to see an EU membership referendum take place.

But Farage is sceptical Cameron will be able to deliver on his pledges for EU treaty change.

“The Cameron offering, frankly, isn’t good enough in the sense that it’s all been kicked into the long grass into 2017 following a renegotiation that looks highly improbable at any level,” he told Sky News.