The reaction of Jean-Claude Juncker, the European Commission president, right, to Brexit has been ‘very damaging’; Angela Merkel, the German chancellor, is said to believe he has ‘become part of the problem’

Jean-Claude Juncker, the president of the European Commission, is under pressure to resign after reportedly “gloating” over Britain’s departure from the EU and describing it as a chance to push for greater EU integration.

Angela Merkel, the German chancellor, is understood to believe that Juncker has become “part of the problem”.

“Juncker has time and again acted against the common interest and his reaction to the British referendum has been very damaging,” a German minister told The Sunday Times.

“This is not a time for institutional bickering, but the pressure for him to resign will only become greater and chancellor Merkel will eventually have to deal with this next year.”

Juncker’s decision to meet Nicola Sturgeon, the Scottish first minister, in Brussels, and to talk