German chancellor Angela Merkel issued a rare public rebuke to David Cameron, after the British prime minister reportedly told an EU summit in Brussels last week that the UK could leave the EU if Jean-Claude Juncker is appointed president of the European Commission.
In a sign of the German chancellor's deep irritation with Cameron over his hardline opposition to Juncker, Merkel said that issuing threats was not part of the European spirit.
Merkel spoke out after a meeting of centre-right EU leaders, hosted by Swedish Prime Minister Fredrik Reinfeldt at his summer retreat in Harpsund.
The three leaders, together with Dutch Prime Minister Mark Rutte, reached agreement on the need for the European Council - the body comprising the 28 EU leaders - to work with the European Parliament on speeding up reform on areas including freedom of movement and liberalisation of digital services.
But Cameron found himself isolated as Merkel said that Juncker was still her preferred candidate for EC president. Rutte and Reinfeldt called for a wide-ranging EU reform programme to be decided before candidates are agreed or blocked.Merkel, who faced a domestic backlash after initially appearing to raise questions about Juncker after the European elections, threw her weight behind the former Luxembourg prime minister and criticised Cameron for issuing threats.
She said after the talks concluded in Harpsund: "I made myself clear by saying that I am for Jean-Claude Juncker. But when I made that statement in Germany I also made the point that we act in a European spirit. We always do that because otherwise you would never reach a compromise.
"Thus we cannot just consign to the backburner the question of the European spirit. Threats are not part and parcel of that spirit. That is not part of the way in which we usually proceed."
Merkel made her remarks after Cameron was asked whether he had issued threats to leave the EU. He came close to confirming that he had made clear in Brussels last week that the appointment of Juncker could act as a major boost to the anti-EU side in his planned in-out referendum in 2017.
Cameron said: "I have a very straightforward approach, which is that I want Britain to stay in a reformed EU. That is my goal. That is what I think is best for Britain and the best for Europe as well.
British officials have not given up hope on blocking Juncker by building a "blocking minority" in the European Council.