Two prominent German politicians on Friday called for banning branches of the far-right Alternative for Germany (AfD) they described as "ethno-nationalist,” days before a pivotal election in Saxony-Anhalt where the party could enter government for the first time.

In a joint article for the Sunday edition of the Frankfurter Allgemeine Zeitung newspaper, Defense Minister Boris Pistorius, from the center-left Social Democrats, and Green veteran Cem Özdemir, the premier of the south-western state of Baden-Württemberg, revived calls for the anti-immigrant AfD to face legal restrictions in four eastern states.

"Based on our personal convictions, we once again urge that proceedings to ban the party be initiated as soon as possible, with a focus on the clearly ethno-nationalist state branches of the AfD in Thuringia, Saxony, Saxony-Anhalt and Brandenburg," the politicians wrote.

Due to their anti-constitutional views, the AfD chapters in all four states are classified as "confirmed" right-wing extremist movements by intelligence agencies, allowing for the party to be monitored by authorities.

Nevertheless, the party has soared in popularity in recent years, benefiting from discontent with the political establishment in Berlin, and it is polling above 40% in Saxony-Anhalt ahead of the election on Sept. 6.

All mainstream parties refuse to work with the AfD, a policy famously known as the "firewall," but successive governments have rejected calls for the party to be banned due to its extremist positions.