Polish security forces have been mobilised across cities in preparation for rallies, in addition to the Belarusian border.
A far-right march has gone ahead on Poland's Independence Day despite a court ban, organisers say.
The November 11 national holiday commemorates the day Poland gained its independence after World War I, but in recent years rallies have attracted nationalist groups, violence, and anti-Semitism.
Last year’s march -- which took place despite a pandemic ban on public gatherings -- saw police use tear gas and rubber bullets in clashes with far-right supporters.
The Warsaw District Court last month upheld a ban on the rally and ruled in favour of the city's liberal mayor Rafal Trzaskowski.
Trzaskowski has stated that Warsaw is "no place to propagate slogans that have all the hallmarks of fascist slogans".
But Konstanty Radziwill, the conservative governor of the region, had earlier approved the 2021 Independence Day march.
Organisers of the rally pledged to appeal the ruling and had insisted the march would go ahead as planned.
Security forces in Poland have been mobilised in the capital and other cities in preparation for the rallies.
Polish troops have also been stationed at the country's eastern border with Belarus amid a tense migration stand-off.
Poland has objected since the summer to the increasing number of refugees and migrants trying to enter the country from Belarus.
The European Union has accused Belarusian President Alexander Lukashenko of encouraging illegal migration to destabilise the bloc.
Bartosz Grodecki, a deputy interior minister, said that a large number of police officers in Warsaw to guard the march will be deployed to the border directly afterwards.
Poland’s ruling Law and Justice (PiS) party has generally shown acceptance of far-right groups since it took power in 2015, offering funds to two groups led by the Independence March Association.
"PiS has... taken responsibility for whatever happens during the march, every fight, every instance of arson," the Left opposition group said on Twitter on Thursday.