Former German Chancellor Angela Merkel has issued rare public criticism of her successor as the country’s center-right leader, the front-runner in Germany’s election next month, for putting to parliament proposals for tough new migration rules that only passed with the help of a far-right party.

Germany’s parliament has narrowly approved a call by Chancellor Olaf Scholz’s main challenger to turn back many more migrants at the country’s borders, with the help of a far-right party.

Germany’s conservative chancellor candidate Friedrich Merz, whose CDU/CSU coalition is leading polls by double digits, upended the election campaign Wednesday by accepting votes from the nationalist Alternative for Germany to pass a hard-line migration resolution through parliament.