A third politician from German Chancellor Angela Merkel's ruling bloc has resigned over allegations of corruption.
Mark Hauptmann, from the centre-right Christian Democratic Union (CDU), faced allegations that he had received payments from the government of Azerbaijan.
The Thuringia MP has denied the accusations of lobbying but announced that he would be stepping down from his position.
"I want to protect my family," Hauptmann told the German daily Die Welt, adding that he was resigning because of the criticism.
"I have never received money, and there has never been any influence on my political actions," he said.
It comes just days after two other members of Merkel's conservative bloc resigned amid allegations they profited from brokering deals to procure face masks early in the pandemic.
The CDU party has seen its support dip in recent opinion polls ahead of crucial state elections in Baden-Württemberg and Rhineland-Palatinate on Sunday.
Chancellor Merkel has backed the efforts of the parliamentary group to clear up the affair of corruption and lobbying by members of the Bundestag.
"The federal government's ability to act is not affected by this," said government spokesperson Steffen Seibert.
The CDU is expected to lose in the two southwestern regions where nearly 11 million voters are set to renew their regional parliaments, just six months ahead of parliamentary elections to choose Merkel's successor as chancellor.