On the 34th anniversary of Poland’s first postwar democratic election, hundreds of thousands of protestors gathered in Warsaw on Sunday for a march that the liberal opposition has framed as a test of its capacity to overthrow nearly eight years of nationalist government later this year.

Crowds marched for at least a mile, carrying banners that read “Free, European Poland,” “European Union yes, PiS no.”

Some people were wearing masks of governing party leader Jaroslaw Kaczynski with the word “shame” printed on them. According to organizers, half a million people marched. Police and local authorities refused to provide an estimate.

“I’m here because freedom is important, because everyone should feel safe, this is a protest of free people, I believe that change is already happening,” Ewa Joachimowicz, a marcher from Chelm in eastern Poland, told Reuters. Opinion polls show an election due after the summer will be closely fought, with Russia’s war in neighboring Ukraine giving a boost to the Law and Justice (PiS) government which has emerged as a leading voice against the Kremlin in Europe.

The opposition has struggled to galvanize support despite widespread criticism at home and abroad of the PiS, which has been accused of eroding the rule of law, turning state media into a government mouthpiece and endorsing homophobia.

Prime Minister Mateusz Morawiecki’s government denies subverting any democratic norms and says its aim is to protect traditional Christian values against liberal pressures from the West and to make the economy fairer.

The opposition sees the legislation as a government attempt to launch a witchhunt against political opponents.

In an unexpected turnaround, President Andrzej Duda, a PiS ally, said on Friday he would propose amendments to the law, which has also drawn criticism from lawyers, as well as the United States and the European Commission.

The EU’s executive said the legislation could effectively ban individuals from holding public office without proper judicial review.

“It’s beyond comprehension,” said Andrzej Majewski, 48, from Slupca in western Poland who was in Warsaw to join Sunday’s protest march.