Huge crowds flooded central Prague demanding Prime Minister Andrej Babis step down over allegations of graft in a protest that organisers and local media claim drew around 250,000 people, making it the largest since the fall of communism in 1989.
The 64-year-old billionaire was charged last year in connection with a two million euro ($2.25 million) EU subsidy scam, while an audit by the European Commission ruled that he has a conflict of interest as a politician and entrepreneur.
The Czech government said earlier this month there were "errors" in the audit from Brussels and Babis has refused to budge.
"Judging from the aerial photos, it looks like we're about 250,000. We'll see how many more people will still arrive," said Mikulas Minar, head of Million Moments for Democracy, the NGO organising the protest, as it got underway.
Police estimates of the size of the crowd were not immediately available.
"We're fed up with what Babis is doing, how he manages the country," Mila Stiburkova, a 39-year-old sales manager from the central Czech town of Sazava, told AFP.
"We don't like him pocketing money and fooling people who trust him," added Stiburkova, who like many protesters, travelled to Prague for the event.
Country plagued with graft
Babis, the second wealthiest Czech according to Forbes, leads the centrist populist ANO movement, which, despite the controversy, won May's elections to the European Parliament.
ANO took office after winning the 2017 general election campaigning on an anti-corruption ticket in the country plagued by graft.
It teamed up with the leftwing Social Democrats to form a minority coalition with tacit backing from the Communists for a parliamentary majority.
Babis, a former Communist, is the first politician since the 1989 fall of Communism in former Czechoslovakia to let the Communists have a role in government.
The Slovak-born 64-year-old is facing charges over EU subsidy fraud after allegedly taking his farm out of his sprawling Agrofert holding to make it eligible for an EU subsidy.
The EU is probing his dual role as a politician and entrepreneur, and Babis also faces allegations that he served as a secret Communist police agent in the 1980s.
Despite the allegations, which Babis fervently denies, ANO -- described as a one-man party by critics -- enjoys a steady 30-percent voter support in opinion polls.
Sunday's rally is the latest in a series of protests against Babis and new Justice Minister Marie Benesova, which started as Benesova was appointed in April.
The organisers, who fear Benesova was appointed to clear Babis of his charges, brought about 100,000 protesters to Prague's central Wenceslas Square in early June as the protests gradually increased.
On its Facebook page, the Million Moments for Democracy group said Babis's "multiple conflicts of interest" were unacceptable.
Besides the resignation of Babis and Benesova, the group also wants Agrofert to return all EU subsidies it received while Babis was involved in the alleged conflict of interest.
