NO2EU campaigners ridiculed grandstanding Prime Minister David Cameron yesterday for playing games in Brussels instead of opposing Britain’s EU membership.

The zig-zagging Mr Cameron phoned Jean-Claude Juncker to congratulate him on running a successful campaign for presidency of the EU Commission.

Yet Mr Cameron had spent the whole of last week proclaiming that Mr Juncker’s appointment would be “a sad moment for Europe” — and that he would fight against it “to the end.”

Downing Street spin doctors claimed that the PM had discussed with Mr Juncker how they could now work together to secure “a fair deal for Britain.”

No2EU spokesman Brian Denny complained: “Mr Cameron is up to the same old tricks. He is playing games with Britain’s future.

“He grandstands and then he backs down.”

Referring to Mr Cameron’s promise of an EU referendum by 2017 if he wins the election, Mr Denny predicted: “Come the referendum, Cameron will campaign for Britain to stay in a neoliberal EU.”

Labour MP and anti-EU campaigner Dennis Skinner declared: “What a mess Cameron’s made of it. What a plonker!

“He has emboldened Mr Juncker by his intervention, and given him victory in a 26 to 2 vote.”

Tory MPs bawled at Labour leader Ed Miliband when he accused Mr Cameron of attempting to solve the problems of the Conservative Party rather than the EU.

Cameron’s renegotiation strategy was in tatters, said Mr Miliband.

“Europe is not un-reformable. It’s just that he cannot do it.”

Mr Cameron told MPs that “last week’s outcome will make renegotiation of Britain’s relationship with the EU harder. But with determination, I believe we can deliver.”