In a guest commentary for "Spiegel Online" on Tuesday, Justice Minister Heiko Maas said that instead of "demonizing the AfD, we must carry out a substantive examination of it."

The right-wing populist Alternative for Germany has enjoyed a surge in support in recent months, with opinion polls suggesting that the AfD now holds 12 to 14 percent of public support nationwide. The AfD's strong gains have coincided with public debate over refugees, as well as with renewed discussion of Islam in Germany. The AfD now holds seats in eight of the country's 16 state parliaments - and looks on course to claim national representation in next year's general elections.

Reflecting upon the AfD's first official manifesto, which was presented in the western city of Stuttgart earlier this month, Maas said the party must "be held to their word."

Anti-Islam manifesto

Included in the AfD's manifesto were calls for a ban on minarets, public calls to prayer and headscarves in public schools. AfD members also voted to include a position against the euro currency, the European Union as a political entity, the presence of nuclear weapons in Germany, and the deployment of soldiers overseas.

"The AFD manifesto is the roadmap to another Germany, to a Germany of yesterday," the justice minister warned on Tuesday.

"Our country has a murky past, but our parents' generation has created a modern Germany: cosmopolitan and liberal domestically, good neighbors and peaceful partners abroad," he wrote.

'Nationalism and isolationism'

The right-wing populists are "not a good alternative for Germany," Maas said, adding that the party's supporters were "spiritual brothers of Vladimir Putin, Donald Trump and Recep Tayyip Erdogan: Nationalist, authoritarian and misogynist."

Since 1949 the target of a "united Europe" has been firmly anchored in the German constitution, Maas wrote, adding that overcoming nationalism was the great lesson of two world wars on German soil. The AfD, on the other hand, is demanding the dissolution of the European Union or Germany's withdrawal from it, Maas wrote.

"Nationalism, isolationism and new limits are their responses to globalization," Maas wrote. "That would not only be politically fatal for our export nation, but also economically, as 60 percent of German foreign trade goes to EU countries. It would cost many people their jobs."

A discriminatory manifesto

The justice minister wrote that the biggest problem with the AfD is the party's stance on religious freedom.

"How else should the sentence 'Islam does not belong to Germany' be understood?" Maas wrote. "If there are claims of a 'below-average level of education' of Muslims and warnings of an 'ethnocultural change' as a result of a high Muslim birth rate, then the line to biologistic racism has clearly been overstepped," he added.

Despite their controversial policies, AfD politicians and party members insist that they're not far-right, but merely injecting "healthy patriotism" into a political landscape that lacks it.