Thousands of people marched through Warsaw to show support for the ruling Law and Justice party following anti-government protests on Saturday.
The demonstrators chanted the name of the party's leader, Jaroslaw Kaczynski, and President Andrzej Duda, an ally of the party, at a rally on Sunday.
It follows protests organised by the Committee for the Defence of Democracy.
The group accuses Poland's government of trying to manipulate state institutions.

Tensions rose in Poland after the conservative Law and Justice party attempted to replace five out of 15 judges of the constitutional court.
The opposition said the move was illegal, with MPs describing it as "a creeping coup d'etat".
The Law and Justice party argued it needed to appoint new judges to ensure a balance of power. It accused the Civic Platform party - which came second in elections after governing Poland for eight years - of refusing to accept the election results.
"We won the election, but we have no right to set laws and remodel Poland," Mr Kaczynski said to the crowds on Sunday.
"This court is supposed to be the stronghold... defending the system, defending all that has been bad and disgraceful in the last 26 years."

BBC