Dresden, the capital of Saxony, has long been viewed as a bastion of the far-right and is the birthplace of the anti-Islam Pegida movement.
Councillors in the city – a contender for the 2025 European Capital of Culture – have now approved a resolution saying more needs to be done to tackle the issue.
But opponents say it goes too far.
What is a ‘Nazi emergency’?
Mr Aschenbach, from left-leaning satirical political party Die Partei, said he believed it was necessary to take action because politicians were not doing enough to “position themselves clearly” against the far-right.
“The request was an attempt to change that. I also wanted to know what kind of people I’m sitting with in the city council of Dresden,” he said.
The resolution acknowledges that “right-wing extremist attitudes and actions… are occurring with increasing frequency” and calls on the city to help victims of far-right violence, protect minorities and strengthen democracy.
Mr Aschenbach said adopting the motion showed the city council’s commitment to fostering “a free, liberal, democratic society that protects minorities and resolutely opposes Nazis.”
How was a ‘Nazi emergency’ declared?
Mr Aschenbach’s resolution was put to a vote by Dresden’s city council on Wednesday night.
The CDU described the resolution as “pure political symbolism” and said the strong wording was a “linguistic error”, German news agency DPA reported.
The CDU did not immediately respond to requests from the BBC for comment.
Germany’s liberal Free Democrats (FDP) backed the legislation, but one councillor criticised the term “Nazi emergency”, saying it would not help Dresden’s application to become a European capital of culture, according to DPA.
Mr Aschenbach said the city was not obliged to take any action following the adoption of his resolution, but that “theoretically, existing measures should be given a higher priority and future decisions should follow this.”
Kai Arzheimer, a German politics professor who has written extensively on far-right extremism, said the resolution’s main impact was symbolic, but that it could mean that more money would be allocated to programmes combating extremism in the future.
“I don’t think that any other German city has declared a ‘Nazi emergency’. Resolutions against right-wing extremism are not so uncommon, however,” he said.
What is Dresden’s connection to the far-right?
Dresden has long been known for its links to the far right.
The state of Saxony has also long been a stronghold of the far-right National Democratic Party of Germany (NPD) and later the far-right Alternative for Germany (AfD) party.
In state elections in September, support for the AfD surged, up 17.8% from 2014 to finish on 27.5%.
Dresden is also where the anti-Islam Pegida (Patriotic Europeans against the Islamisation of the West) movement began in 2014, and where it continues to hold rallies.
Pegida supporters say people need to “wake up” to the threat of Islamist extremists. They want Germany to curb immigration and accuse the authorities of failing to enforce existing laws.
The movement has spurred large counter-rallies in the city.