Chancellor Olaf Scholz's main challenger in Germany's upcoming election plans to put proposals for a tougher migration policy to parliament on Wednesday, a maneuver aimed at piling pressure on the governing parties that has brought accusations that he's breaking commitments to shun the far right.

Opposition leader Friedrich Merz put migration in the focus of the campaign following a knife attack a week ago in the Bavarian city of Aschaffenburg by a rejected asylum-seeker, which left a man and a 2-year-old boy dead.