Hungary's center-right opposition Tisza party kept an eight-point lead over Prime Minister Viktor Orban's governing nationalist Fidesz party in January, a poll showed on Monday, ahead of a parliamentary election set for April 12.

Orban is facing the biggest challenge to his grip on power since Fidesz swept to victory in 2010, although the outcome remains highly uncertain.

Tisza is led by former government insider Peter Magyar who has said his party will tackle corruption, unlock billions of euros in frozen European Union funds to boost the economy, and firmly anchor Hungary in the EU.

The April vote will have major implications for Europe and its far-right political forces.

Orban, an ally of President Donald Trump, has often clashed with the EU on a range of issues while maintaining cordial ties with Russia and criticizing Ukraine. The EU accuses Orban of eroding democratic values in Hungary, which he denies.

The latest poll, conducted between Jan. 21-24 by Publicus Institute and published by daily newspaper Nepszava, showed that 48% of decided voters supported Tisza while 40% backed Fidesz, unchanged from December.

Besides the two major parties, only the far-right Our Homeland (Mi Hazank) would surpass the 5% threshold required for entry into parliament, the survey found.

The poll also found that 63% of voters thought Hungary was on the wrong track. That figure rose to 71% among pensioners, a key demographic, which Orban has targeted with a pension top-up.

Most polls have shown Fidesz trailing Tisza despite voter-pleasing measures after three years of economic stagnation in Hungary, which has also endured the EU's worst inflationary surge following Russia's invasion of Ukraine.

However, pro-government pollsters show a Fidesz lead.

A second survey published on Monday by the pro-government Nezopont Institute showed Orban had a 46% approval rating compared with 35% for Magyar.

Nezopont, which did not survey party preferences in the poll conducted between Jan. 26-27, said support for Orban was especially high among elderly and rural voters.