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.

German election frontrunner Friedrich Merz succeeded on Wednesday in getting a motion passed in parliament that calls for a migration crackdown including the rejection of asylum seekers at the country's land borders.

With less than four weeks before Germany’s federal election, Chancellor Olaf Scholz and his conservative challenger Friedrich Merz, who is leading polls, will take their contentious battle over how to crack down on illegal migration to parliament.