German conservatives under likely next chancellor Friedrich Merz vowed on Monday to move quickly to try to form a coalition after winning the most votes in a national election that saw far-right and far-left parties gain support from disaffected voters.

"The members have the final say," said party chairman Lars Klingbeil. "The members will make the final decision." Klingbeil is expected to take on leadership of the SPD's much reduced parliamentary group on Wednesday before representing the party in coalition talks with the CDU.

The 69-year-old faces lengthy coalition negotiations after the far-right Alternative for Germany (AfD) surged to a historic second place in a fractured vote following the collapse of Chancellor Olaf Scholz's unloved three-way alliance.