PRAGUE — In the square in the heart of Prague, where crowds gathered three decades ago in their bid to wrest freedom from Communist rule and where independence was proclaimed seven decades before that, protest songs rang out again on Tuesday night.
Tens of thousands of men, women and children, coming from across the Czech Republic, waving flags and carrying signs attacking the government, gathered for what they said was yet another struggle for the soul of their democracy.
What started six weeks ago as a relatively contained protest — over the appointment of a justice minister many believe will protect Prime Minister Andrej Babis from potential fraud charges — has grown into something broader and possibly harder to control. Organizers said Tuesday that as many as 120,000 people had attended the protest, a count that would make it one of Prague’s largest demonstrations since 1989.
“This is about more than just corruption,” said Tomas Peszynski, 44, holding the corner of an oversize European Union flag. “This is about an abuse of the system of government and a fight to protect the institutions of democracy.”
Mr. Babis has responded with his characteristic bravado — he said the large crowd size was a reflection of the nice weather — and he has condemned those leading investigations into his business dealings as being part of vast political conspiracy.
“We have Babis hysteria again,” he recently told lawmakers. “Try to do something for the people instead, don’t just take a swipe at Babis.”
Mr. Babis has been battling accusations of corruption for years and, in an interview last year, he did not hide his anger, saying it was impossible to defend himself from the constant stream of attacks. But he has proved resilient, having already survived a no-confidence vote in Parliament.
However, the large demonstrations — with organizers promising more in the weeks to come — present a different challenge.
In neighboring Slovakia, months of protests fueled by anger over corruption forced the government to collapse and paved the way for a newcomer, Zuzana Caputova, to win the presidential election this year. The success of the movement there was closely watched by organizers in their brother nation, as the two countries have called themselves since their peaceful separation in 1993.
In fact, Mr. Babis was elected to Parliament in 2013 in part because of a promise to battle corruption.
With a net worth estimated at around $4 billion, he presented himself as someone who could not be corrupted. And as a businessman who came from outside the familiar cast of political elite tainted by years of scandal, he promised a new era.
The voters agreed. In 2017 parliamentary elections, Mr. Babis and his party won a resounding victory, and he was named prime minister.
Now, many accuse him of betrayal, and worse, engaging in an effort to bend the legal system to protect himself as he faces increased scrutiny over how his sprawling conglomerate — which includes more than 200 businesses, from agriculture to media — used funds provided by the European Union.
“We believed what he was saying when he was first elected,” said Dagmar Pavelkova, 27. “But there were just too many stories about his corruption and now he is trying to manipulate the legal system to get off.”
She traveled three hours from Hranice na Morave with her husband, who carried a sign with the famous words of the anti-Communist hero Vaclav Havel: “Truth and Love Will Prevail.”
Mr. Babis has been dogged by accusations of corruption for years, but the recent protests began in April, shortly after the police recommended that he face fraud charges in connection with a European Union subsidy to finance construction of a resort near Prague, called the Stork’s Nest.
The next day, the justice minister, Jan Knezinek, resigned. He was replaced by Marie Benesova, who is close to the country’s president, Milos Zeman, an ally of Mr. Babis. The move set off immediate outrage.
Under the Czech system, while the police can recommend an indictment, only the state’s prosecutor, who is appointed by the justice minister, can file charges.
For his part, Mr. Babis dismissed the police investigation as a politically orchestrated attack.
An audit by the European Commission made public last week has been harder to ignore. It found that Mr. Babis’s company, Agrofert, has benefited from European Union funds. Since he stands to gain from the success of his company — even though he maintains he has divorced himself from its operation — the audit found that his impartiality was compromised, first when he served as finance minister and later when he became prime minister.
“I strictly reject this opinion and I will fight for it to be changed,” Mr. Babis said. “The Czech Republic certainly won’t have to return any subsidies. There’s no reason for that, because I’m not violating any Czech or European legal norms.”
Speaking in a session of Parliament on Tuesday, Mr. Babis stepped up his attacks on his opponents.
“I consider the audit an attack on the Czech Republic, an attack on the interests of the Czech Republic,” he thundered. “It is a destabilization of the Czech Republic.”
While the crowd of protesters on Tuesday was large, Mr. Babis’s Anos party still has a solid base of support. In the recent European Parliament election, affiliated candidates got some 20 percent of the vote, the highest of any party.
But more than anything else, the results showed how fractured the political landscape in the country has become.
The Social Democrats, who were at the center of Czech politics for a quarter-century, are now just one of a handful of parties fighting for the vote of an angry and disillusioned electorate.
Many of those on the square on Tuesday rejected party labels.
Jitka Cvancarova, a famous Czech actress who spoke from the stage in front of the National Museum, said that values should be at the core of any decent society.
“Mr. Babis,” she said, addressing the prime minister directly. “You can probably buy a lot, but you cannot buy our honor, our hearts or our freedom.”