Hungary’s parliament has voted to lift the immunity of opposition leader Péter Magyar, opening the way for a criminal investigation against him.

The vote passed 139 to 0 on September 28, according to reports. Magyar, who leads the Tisza party challenging Viktor Orbán’s government, denies any wrongdoing.

Prosecutors want to investigate allegations that Magyar stole a mobile phone and threw it into the Danube. His supporters call the case politically motivated.

Lifting immunity is not a charge or a conviction. It removes the legal protection that shielded Magyar from prosecution as a member of the European Parliament.

Opposition figures say the move is an attempt to hobble Orbán’s strongest challenger ahead of elections. The government insists prosecutors are acting independently of politics. European observers are watching the case closely as a test of Hungary’s rule of law.