The pretender came out fighting on Wednesday night at the most important hustings in the race to succeed Angela Merkel. Friedrich Merz, an old rival of the German chancellor, is vying to make a remarkable comeback by replacing her as leader of her Christian Democrat party (CDU).

And he didn’t hesitate to attack her record as leader, claiming she has abandoned the party’s conservative profile.

“You don't need to copy every single Social Democrat policy, that just doesn't have to happen,” he said, referring to the Germany’s main centre-Left party.

By the time Mr Merz had finished a speech in which he appealed for more funding for the Germany military, several audience members leapt up in a standing ovation.

Wednesday's hustings in Düsseldorf was make-or-break for Mr Merz, who retired from politics in 2009 after losing to Mrs Merkel in a battle for control of the party.

He is locked in a three-way race to take over as CDU leader when Mrs Merkel stands down next month and, if polling is to be believed, he is neck-and-neck with Annegret Kramp-Karrenbauer, the current party chairman and a Merkel loyalist.

The third candidate, Jens Spahn, is lagging far behind.