DAVID Cameron's charm offensive to renegotiate the terms of Britain's EU membership hit a diplomatic brick wall when he suffered a series of setbacks in meetings with his continental counterparts.

The prime minister continued his attempts to build support for his renegotiation plan in a round of bilateral talks with fellow EU

leaders during a Europe-Latin America summit in Brussels.

But he was warned by Belgian Prime Minister Charles Michel that his country had a series of "red line" issues - including free movement of labour - on which it would not compromise.

There was also resistance to elements of his plans from the leaders of Romania, Spain and Finland.

"There can't be any ambiguity: at the end of the process, the result can't be that we dismantle Europe," Mr Michel was quoted as saying by the Belgian Le Soir news website following the leaders' talks.

"For Belgium there are red lines: the principles of free movement and non-discrimination between EU citizens are inviolable. Neither can there be any veto given to national parliaments; that would be the end of the European Union," he declared.

Mr Michel, who described their discussion as "open and frank", said he could not rule out the prospect that the re-negotiation would end with Britain voting to leave the EU in Mr Cameron's referendum.

"I can't rule anything out. But it is the British who have pushed the referendum button. It's democracy and no-one in Europe argues with that. I recognise that, on Europe, British public opinion see things differently to ours."

The Belgian premier added: "But if the British think that it is possible for them to enjoy only the advantages of EU membership while the drawbacks are only for the rest, that will not work."

Meantime, Mariano Rajoy, the Spanish PM, was quoted as having told Mr Cameron that treaty change "can't be done" while Finland's Juha Sipila said he was unwilling to enter a "carousel" of treaty negotiations.

Klaus Iohannis, the Romanian President, told Mr Cameron he opposed "discriminatory" measures on benefits.

Downing Street sought to downplay the collective rebuff, saying the PM expected to hear "lots of views expressed during this process".