Tens of thousands of protesters in Budapest have gathered against the government of Viktor Orban, led by lawyer Peter Magyar, who recently launched a political movement to challenge the prime minister.

The march was led by Magyar, who used to be married to Orban’s former justice minister Judit Varga and plans to launch his own party.

Protesters wore the national colours or carried the national flag, symbols Orban’s party used for the past two decades.

Magyar became known in February for his incendiary comments about the government’s inner workings, accusing minister Antal Rogan of running a propaganda machine.

Prosecutors are now investigating his statements. The protest 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 in February.

Pollster Median reported that 68% of voters have heard of Magyar’s entry into the political field and 13% said they were likely to support his party.