A prominent ally of German Chancellor Angela Merkel has threatened to sue her government over its open door policy towards refugees.
Bavarian state premier Horst Seehofer said he would send the federal government a written request within the next two weeks to restore "orderly conditions" at the nation's borders. Bavaria is the main entry point for refugees.
"If it doesn't follow, the state government will have no other choice but to file a suit at the Federal Constitutional Court," Seehofer told Der Spiegel magazine on Saturday.
Seehofer has issued a series of ultimatums to Merkel in recent months to press her into taking immediate action to limit the influx of refugees, only to back down at the last minute.
His comments reflect growing doubt among Germans about Merkel's "we can do this" mantra in the face of Europe's biggest migrant crisis since World War Two, especially since sexual assaults in Cologne on New Year's Eve were blamed on refugees.
Merkel's popularity has dropped since the assaults, a poll showed on Friday.
On Thursday, a Bavarian politician has sent a bus carrying dozens of refugees to Chancellor Angela Merkel's office in Berlin to protest her policy towards refugees.
Germany is struggling to cope with the large number of refugees arriving daily. Since the beginning of last year, more than a million refugees mostly fleeing war in the Middle East and Africa have arrived in Germany, while thousands more continue to arrive every day.