BRUSSELS (Reuters) - David Cameron will make a last-ditch stand against the nomination of Jean-Claude Juncker for European Commission president on Friday, enforcing a point of principle that raises the risk of Britain leaving the European Union.
The British prime minister has made his opposition to Juncker abundantly clear. He sees the former Luxembourg premier as lacking the will and the skills to overhaul the EU and has told fellow leaders they are making a mistake in backing him - warning of unspecified 'consequences' if they persist.
The dispute is one of the most public and personal the European Union has experienced in a decade, damaging efforts to present a united front at a time when the bloc is recovering from an economic crisis and keen to bolster its global image.
Despite Cameron's forthright opposition to Juncker, whose center-right political group won European Parliament elections last month, Britain has failed to convince almost any of the 27 other member states to support its position.
Juncker's nomination will be discussed over lunch on the second day of an EU summit, which began on Thursday with a show of modern European unity in a ceremony in the Belgian town of Ypres to commemorate the centenary of World War One.
As well as the Commission presidency, one of the EU's most powerful jobs with sway over legislation affecting 500 million people, the summit will discuss energy policy and sign free trade and political association agreements with Ukraine, Georgia and Moldova, increasing EU influence in the ex-Soviet east despite bitter opposition from Moscow.
While decisions among EU leaders are normally taken by consensus, Cameron wants a vote on Juncker - an unprecedented move officials wanted to avoid but which now looks inevitable.
Diplomats say that if a vote is held, Britain will lose it by 26 votes to 2, with only Hungarian Prime Minister Viktor Orban backing Cameron. And even Orban's support is not certain.
British officials acknowledge that Cameron will more than likely lose, but say the prime minister is determined to take a stand on principle, opposing not only Juncker as a candidate but the process that led to his selection - giving the strongest voice not to national governments but to the EU's legislature.
"My message to my fellow heads of government and heads of state is that this approach that they're contemplating taking is the wrong approach for Europe," Cameron said on Thursday as he arrived for the Ypres commemoration, where all the leaders stood shoulder to shoulder to honor the fallen in the Great War.
"They are contemplating choosing someone who I think will struggle to be the voice of reform and change in Europe. When the public in Europe and our nation states are crying out for reform, they're about to take what I think is the wrong step."
Opinion polls show that many British voters support Cameron taking a hard line on Europe. With the prime minister battling to shore up support for his Conservative party and facing an election next year, that popular support is critical.
But it leaves Cameron in an uncomfortable position towards his fellow leaders, many of whom are now openly concerned about the possibility of Britain moving inexorably toward the exit.
Cameron, many of whose own party favor a British exit from the EU, or "Brexit", has promised voters a referendum on leaving the bloc by 2017 - if he wins re-election next year.
A key threat to his re-election is the rise of the UK Independence Party, which campaigns for leaving the EU and which topped last month's European Parliament election in Britain.
"We’re all now responsible for whether the United Kingdom can stay inside the European Union," said Swedish Prime Minister Fredrik Reinfeldt, a regular ally of London who initially sided with Cameron over Juncker. "I'll do whatever I can for Britain to stay inside the European Union."
The problem is that if Juncker, a veteran Brussels dealmaker who is committed to a more federal Europe, ends up heading the Commission, it will be harder for Britain to renegotiate its relationship with the EU, something Cameron has promised to do in advance of putting membership to a referendum.
British officials concede that Juncker may make it harder to get a renegotiation of membership terms and his presence may also increase the likelihood that Britons vote to leave the EU.
Additional reporting by Kylie Maclellan; Editing by Alastair Macdonald