UK's David Cameron says voters did not choose Jean-Claude Juncker for top EU job

British Prime Minister David Cameron on Friday made his strongest public intervention yet to stop Jean-Claude Juncker becoming the next European Commission president, saying it was nonsense to suggest that European voters had chosen him.

Cameron does not want Juncker to get the job as he views him as too much of an old-style federalist who will obstruct his push to reform the European Union and persuade British voters of the merits of staying within the 28-nation bloc.

Cameron has promised to renegotiate Britain's ties with Brussels, ahead of holding an in/out referendum on the country's EU membership by 2017 if he wins a national election next year.

While he has made his opposition to Juncker clear, repeatedly saying the job should go to someone more reform-minded, he has largely shied away from referring to him by name.

On Friday the prime minister warned against the suggestion of some in the European Parliament that the job should go to the candidate put forward by the party which won the most seats. Juncker has the support of the European People's Party, the largest centre-right political grouping in the parliament.

"It is not an attack on Mr Juncker, an experienced European politician, to say this is nonsense. Most Europeans did not vote in the European Parliament elections. Turnout declined in the majority of member states. Nowhere was Mr Juncker on the ballot paper," Cameron wrote in an article which his office said would be published in several European newspapers on Friday.

Cameron said that even in Germany, where the concept of the lead candidates was most well publicised, only 15 percent of voters knew Juncker was in the running.

"He did not visit some member states. Those who voted did so to choose their MEP not the Commission president. Mr Juncker did not stand anywhere and was not elected by anyone," he said.

EU leaders are expected to decide on their candidate for the presidency of the EU executive - a job with major influence over policy affecting 500 million Europeans - by a summit at the end of this month.

To accept that Juncker had been chosen by European voters would set a dangerous precedent, Cameron said.

"It would politicise the European Commission," he wrote. "It would be a green light for those who want to breach the EU's rules by the backdoor. Rules that have been ratified by our national parliaments and laid down in international law."

Cameron, whose objection to Juncker has put him at odds with German Chancellor Angela Merkel, has been trying to rally support among other European leaders to block the former Luxembourg prime minister from getting the job.

He held talks in Sweden earlier this week with Merkel, Swedish Prime Minister Fredrik Reinfeldt and Dutch premier Mark Rutte, and has also called Italian Prime Minister Matteo Renzi and Hungarian Prime Minister Viktor Orban.

"Now is the time for Europe's national leaders to have the courage of their convictions by standing up for their place in the EU and what is right for Europe's future," Cameron wrote. "Now is the time to propose a candidate who will convince Europe's voters we are acting upon their concerns."

(Editing by Alison Williams)