Péter Magyar's party, Tisza, won more than 53% of the vote in the legislative elections, far ahead of the prime minister's Fidesz, which managed barely 38%. Tisza is expected to secure 138 out of the 199 seats in Parliament, giving it a constitutional supermajority.

Most polls favour Péter Magyar, who fronts a grassroots party, but PM Viktor Orbán has been in a defiant mood.

Péter Magyar's victory was expected to transform political dynamics within the EU, where Orbán had upended the bloc by frequently vetoing key decisions.