It was the first time since Poland's transition from communism in 1989 that a sitting of the lower chamber of Parliament and a budget vote were held outside of the main chamber.
"In my opinion, yesterday's events were an illegal attempt to seize power," Mariusz Blaszczak, Poland's Interior Minister, said of opposition MPs.
Opposition leaders claimed having a parliamentary vote outside the chamber was both illegal and a violation of the Polish constitution. Warsaw police confirmed physical force was used to remove protesters.
At the heart of the issue was free access to information. In the 27 years of Poland's democracy, journalists have been a constant presence in the parliament's halls. Banned from the main assembly room, they can grab politicians for interviews in the halls.
The ruling party, which is under European Union scrutiny for policies deemed anti-democratic by opponents, plans new rules starting January 1 that would drastically limit reporters' access in Parliament.
Kaczynski denounced the obstruction of Parliament as "hooliganism" and threatened protesters with consequences. "We will not allow ourselves to be terrorised," he said.