WARSAW, Poland (AP) -- Hundreds of thousands of people marched in an anti-government protest in Poland's capital on Sunday, with citizens traveling from across the country to voice their anger at officials who they say have eroded democratic norms and created fears that the nation is following Hungary and Turkey down the path to autocracy.
Warsaw Mayor Rafal Trzaskowski, who belongs to the opposition party that led the march, estimated that 500,000 people took part. The Onet news portal estimated there there were at least 300,000 at the march's culmination.
Large crowds also gathered in Krakow and other cities across the nation of 38 million people, showing frustration with a government that critics accuse of violating the constitution and eroding fundamental rights in Poland.
Former President Lech Walesa, the leader of the Solidarity movement that played a historic role in toppling communism in Poland, marched alongside the leader of the opposition Civic Platform party, ex-Prime Minister Donald Tusk.
Walesa and Tusk are reviled by the ruling Law and Justice party led by Jaroslaw Kaczynski, and the Warsaw crowd chanted "Democracy!" and "Constitution!"
The rally started at Prime Minister Mateusz Morawiecki's office and ended up at the Royal Castle, where Tusk hailed the turnout and pledged to fight to win an autumn election.
"We are going to these elections to win and to right human wrongs. I promise you victory, a settlement of evil, compensation for human wrongs and reconciliation among Poles," Tusk told the crowd.
The government spokesman, Piotr Mueller, accused Tusk and Walesa of "trying to overthrow the government."
Tusk had called on Poles to march with him for the sake of the nation's future -- a message that resonated for Radek Tusinski, 49, who arrived with his wife and two children. A handmade sign reading "I cannot give up freedom" was attached to their baby stroller.
Tuskinski said that he worries about the creeping return of an authoritarian system similar to what he remembers from his childhood.
"We want a free country for our children," he said.
Supporters of the march have warned that the election might be the nation's last chance to stop the erosion of democracy under Law and Justice amid growing fears that the fall election might not be fair.
In power since 2015, Law and Justice has found a popular formula, combining higher social spending with socially conservative policies and support for the church in the mostly Catholic nation.
However, critics have warned for years that the party is reversing many of the achievements made since Poland emerged from communist rule in 1989.
The U.S. government has intervened at times when it felt the government was eroding media liberties and academic freedom in the area of Holocaust research.
Critics point mainly to the party's step-by-step takeover of the judiciary and media, and fear that Law and Justice could eventually force Poland to leave the 27-member European Union.
A clampdown on abortion rights has triggered mass protests. Some also voiced anger at double-digit inflation in the country. Poland's government blames Russia's war in Ukraine and the COVID-19 pandemic, but economists say its spending policies have accelerated spiraling prices.
Barbara Dec, 26, and her grandmother left their hometown of Zielona Gora at 4:30 a.m. and traveled seven hours on a bus organized by Civic Platform to protest.
Dec held up a cardboard sign that read, "I am afraid to have children in Poland."
"Women have lost the right to have an abortion even when the fetus is terminally ill, and some women have died," she explained. "And I am also afraid I couldn't manage financially."
The march was held on the 34th anniversary of Poland's first partly-free election. The protest was seen as a test for Tusk's Civic Platform, a centrist and pro-European party which has trailed behind Law and Justice in polls.
However, the passage of a contentious law last month seems to have mobilized greater support for Tusk. Poland is expected to hold a general election in October, though a date hasn't been set.
The law allows for the creation of a commission to investigate Russian influence in Poland. Critics argue that it would have unconstitutional powers, including the capacity to exclude officials from public life for a decade. They fear it will be used by the ruling party to remove Tusk and other opponents from public life.
President Andrzej Duda, who signed the law on May 29, proposed amendments to it on Friday. In the meantime, the law will take effect with no guarantees that lawmakers in parliament will weaken the commission's powers.
Some Poles say it could come to resemble the investigations of Joseph McCarthy, the U.S. senator whose anti-communist campaign in the early 1950s led to hysteria and political persecution.
That fear was underlined last weekend when Kaczynski was asked by a reporter if he still had trust in the defense minister in connection with a Russian missile that fell in Poland in December.
"I am forced ... to view you as a representative of the Kremlin," he replied. "Because only the Kremlin wants this man to stop being the minister of national defense."
The media freedom group Reporters Without Borders expressed concerns that the commission "could serve as a new weapon for this type of attack, in which doubt is cast on journalists' probity in an attempt to smear their reputation."
Tusk, who once served as European Council president, had called for the march weeks ago, urging people to demonstrate "against high prices, theft and lies, for free elections and a democratic, European Poland."
Law and Justice sought to discourage participation in the rally with a video spot using Auschwitz as a theme -- drawing criticism from the state museum that preserves the site of the Nazi German death camp.