The publication said the reason for this was not the reluctance of British Prime Minister David Cameron to pay an additional contribution to the budget of the European Commission of over EUR 2 billion.

Instead, the main worry is that Cameron is looking for a way to restrict the number of migrants from the EU to the UK. According to Der Spiegel, this is a clear violation of the main parts of EU treaties on freedom of movement.

According sources in the German government, during a tête-a-tête meeting with Cameron at a recent EU summit, Merkel made it clear that the UK could reach a "point of no return" if Cameron continued to press his migration initiative on the EU.