Supporters of the far-right Alternative for Germany party are gathering for a march in central Berlin against Chancellor Angela Merkel's government, while opponents are mobilizing for counter-protests.
Alternative for Germany, known by its German acronym AfD, is the biggest opposition party after winning 12.6 percent of the vote to enter the national parliament last year on anti-migrant and anti-establishment sentiment. Its march Sunday, an unusual move for a German political party, is headlined "Germany's Future."
AfD supporters plan to march from the capital's main station to the landmark Brandenburg Gate. About 2,000 police officers were in place to prevent trouble.
Groups that planned to turn out against AfD include artists and a coalition of Berlin music clubs hoping to "blow away" the party with loud techno beats.
Two thousand extra police officers, including those from 10 other German states, are being deployed to prevent any violence between the two sides.
The AfD have said that about a thousand people could turn up for their "A Future for Germany" rally. Thousands more were expected at the anti-AfD demonstration, with one umbrella group called "Stop the Hate" aiming to block the AfD supporters' route.
Activists on one radical left-wing website urged others to "sabotage the AfD march by all means possible."
"Freedom of assembly applies to everyone," Berlin police spokesman Thomas Neuendorf told dpa earlier this week. "Anyone who obeys the law can demonstrate. But every group must also accord that right to others."
The AfD demo is due to start at midday (1000 GMT) at the city's central station and end with a rally at the famous Brandenburg Gate, just meters from the German parliament.
The AfD won 12.6 percent of the vote in the September 24 national election after campaigning on a tough anti-foreigner and anti-Islam platform, propelling the young party into the German Bundestag for the first time.
Following the formation of a grand coalition government by the country's two biggest parties, the AfD is the official opposition party in the Bundestag.
