The migrant issue has come back to bite Angela Mekel with a vengeance this weekend, as she faces last-ditch talks to save her government and a rift with a coalition partner over asylum policy that could bring about the end of her political career.

But the timing of this crisis has as much to do with a long-running and bitter personal rivalry at the heart of German politics as the fact that the numbers of migrants flocking towards Europe are rising again.

The dispute pits Mrs Merkel against Horst Seehofer, the interior minister who has long been her bete noir and the most outspoken domestic critic of her “open-door” refugee policy.

Mr Seehofer wants to turn away migrants at the German border, but Mrs Merkel has blocked the policy. A furious Mr Seehofer is threatening to impose it unilaterally as interior minister — daring Mrs Merkel to sack him or back him.