Members of Germany’s junior governing party have chosen a left-leaning duo as their new leaders, a decision that could endanger the future of Chancellor Angela Merkel’s troubled coalition.

Norbert Walter-Borjans and Saskia Esken beat the rival team of vice-chancellor Olaf Scholz and Klara Geywitz in a run-off ballot of Social Democrat members, according to results announced on Saturday.

Mr Walter-Borjans and Ms Esken won the support of 53% of members who voted, with just over 45% backing their rivals.

Their appointment still needs the formal approval of a party congress next week, which is also expected to consider whether the party should stay in the “grand coalition” of Germany’s traditional big parties led by the centre-right Ms Merkel.

Germany Politics
Mr Walter-Borjans and Ms Esken, centre, were favoured over Olaf Scholz and Klara Geywitz, right (Kay Nietfeld/dpa/AP)

While Mr Scholz and Ms Geywitz strongly favoured staying in the coalition, Mr Walter-Borjans and Ms Esken have sounded much more sceptical and advocate changes to the coalition agreement.

The Social Democrats have been without an elected leader since Andrea Nahles quit in frustration nearly six months ago. The party decided to ask its 426,000-strong membership who should take on the task of pulling it out of a lengthy poll slump.

The new leaders are not household names to many Germans.

Mr Walter-Borjans is best-known for a 2010-2017 stint as finance minister of North Rhine-Westphalia, Germany’s most populous state, during which regional authorities purchased data on potential tax cheats with money hidden in Swiss bank accounts.

Ms Esken is a federal politician.

After the results were announced, she said none of the would-be leaders had been “great friends” of the coalition and she noted that all had said they did not want to extend it beyond the end of the current parliamentary term, due in 2021.

Angela Merkel
Angela Merkel’s party said it looks forward to continued co-operation with the Social Democrats (Markus Schreiber/AP)

But she and Mr Walter-Borjans – who unlike some contenders eliminated in the first round of voting have not clearly advocated a fast exit – left open what exactly their position will be on the coalition’s future.

“We didn’t let ourselves be nailed down to the question of everything coming down to the question of fleeing (the coalition) or staying in permanently,” Mr Walter-Borjans said.

“We have said clearly that this is about substance; we have said that we must do more on climate, we have said that there must be massive investment.

“We will once again name the points that are important to us and then have the party congress decide what can wait, and what must be implemented so urgently that we raise the question of the coalition because of it.”

Paul Ziemiak, general secretary of Ms Merkel’s Christian Democratic Union, said he looks forward to “trusting co-operation for the good of our country”.

He added: “We want to govern Germany well, we created a basis for that and this internal decision by the Social Democrats has changed nothing about the basis of the ‘grand coalition’.”