Tens of thousands protested against the government of Viktor Orban in downtown Budapest on Saturday, led by a lawyer formerly close to the administration who recently launched a political movement that aims to challenge the prime minister.
Protesters marched to parliament in the unusually warm spring weather, some of them shouting "we are not scared" and "Orban resign!"
Many wore the red-white-green national colours or carried the national flag, symbols that Orban's party used as their own for the past two decades.
"These are the national colours of Hungary, not the government's," said 24-year-old Lejla, who travelled to Budapest from Sopron, a town on the country's western border.
The march was led by Peter Magyar, 43, who used to be married to Orban's former justice minister Judit Varga and who eventually plans to launch his own party.
Three protesters interviewed by Reuters said Magyar appealed to them because he had been close to the Orban government and has an inside knowledge of how it works.
"We had known that there is corruption, but he says it as an insider and confirmed it for us," said Zsuzsanna Szigeti, a 46-year-old healthcare worker wearing a Hungarian flag that covered her entire body.
She said she was concerned about the education and the healthcare systems, and worried about corruption. "I trust that there will be a change," she said.
Magyar became widely known in February when he delivered incendiary comments about the inner workings of the government. He accused Antal Rogan, the minister who leads Orban's office, of running a centralised propaganda machine.
He also published a recording of a conversation with his ex-wife where Varga detailed an attempt by a senior aide to Orban's cabinet chief to interfere in a graft case. Prosecutors are now investigating the statements.
The probe comes at a politically sensitive time for Orban ahead of European parliamentary elections in June, and follows a sex abuse scandal that brought down two of his key political allies - the former president and Varga - in February.
According to data by pollster Median, published by news weekly HVG in mid-March, 68% of voters have heard of Magyar's entry into the political field and 13% of those said that they were likely to support his party.
