The CDU party chief, who leads in the polls to become the next chancellor, said he would collect votes from all parties to push his five-point migration plan through parliament despite Chancellor Olaf Scholz's strong opposition.

The conservative leader wants to impose strict border controls after knife killings in Aschaffenburg this week.

Former German chancellor Angela Merkel has criticized her centre-right Christian Democrats (CDU) for passing a motion in parliament calling for hard-line reforms to migration policy with the support of the far-right Alternative for Germany (AfD).