Violence is overshadowing the political debate
Germany's unions are using the wider May Day protests to vent their anger against the economic reforms being imposed by Chancellor Gerhard Schroeder.
Trade unions in Germany are particularly angry about Mr Schroeder's cost-cutting package that targets the welfare state.
"Yes to reforms. Not to dismantling the welfare state!," the DGB trade union umbrella group said in its call for protests.
The union demonstrations are separate to violent clashes overnight that led to almost 100 people being detained and 29 police officers being injured.
Stuck in the doldrums
The German economy is wrestling with a budget deficit spiralling well beyond the 3% limit laid out in European Union agreements, as well as stubbornly high unemployment of 11% of the workforce.
Economic growth this year is forecast at just 0.4% and many analysts fear that the eurozone's largest economy may slip back into recession.
Mr Schroeder has made a series of promises on how to revive the ailing economy, including trimming back state benefits and making it easier to fire people.
But the unions - together with some left-wing members of Mr Schroeder's own party - are vigorously opposed to such changes.
Trade unions have been using 1 May to call for better rights for workers for more than 100 years.
But the violent street fights in Berlin overnight are likely to overshadow any political debate.
This year, unions have also called for an additional nationwide day of protests on 24 May to highlight their dislike of the proposed reforms.