People march during an anti-government demonstration organized by main opposition parties in Warsaw, Poland, Saturday, May 7, 2016. Kacper Pempel/Reuters

A massive march swept across Warsaw, Poland, on Saturday, prompted by what protesters see as increasing threats to the nation’s democratic constitutional foundations and membership in the European Union.

The ralliers warned that the government, led by the conservative Law and Justice (PiS) party, has begun to erode the rule of law and push the former Soviet-dominated country back toward Russian influence.

The protest stretched 2 miles, Reuters reported, winding through a ceremonial boulevard at the heart of Poland’s capital. While police estimated attendance at 45,000, officials aligned with the opposition Civic Platform (PO) party gave the much higher tally of 200,000, calling it the largest demonstration Poland has seen since its rejection of Communist rule in 1989.

In recent months the PiS has tightened its grip on national government institutions, including the judiciary, causing a widening rift between Poland’s top judges and its ruling party, which took power last year. Government reforms aimed at consolidating judicial power have drawn fierce criticism from opposition parties and a stern rebuke from the EU’s executive Commission, which began a process last month to formally sanction Poland over “rule of law” violations.

A woman holds a sign that reads “Do not hurt me, President,” during protests in Warsaw, Poland, on Saturday, May 7, 2016. Kacper Pempel/Reuters

Protesters at the march chanted “We say ‘no’ to the rotten change” and “Free judge, free Poland,” the Associated Press reported. “We will not allow for the nightmare of authoritarian rule to happen,” PO leader Grzegorz Schetyna told those assembled. A similar rally took place in March.

The march also highlighted Poland’s increasingly contentious relationship with the EU, strained by the ruling party’s political reforms and outright refusal to accept refugees. Pro-EU parties in Poland have expressed concerns that the standoff could endanger European unity and lead Poland back toward Russia’s sphere of influence.

“Only two trains leave from the historic station at which Poland is standing. One is the European Express. The other is the Trans-Siberian Railway,” Kamily Gasiuk-Pihowicz, spokeswoman for the opposition Modern party, told protesters.

The PiS has rejected the notion that Poland’s membership in the EU has been at all endangered. “We want to be a member of the European Union, because we want to have an influence on Europe’s fate,” PiS leader Jaroslaw Kaczynski said in a video released Saturday. “But our position depends above all on our strength. We have to gain a strong position.”