Romania's Social Democrat Prime Minister Marcel Ciolacu faced calls to resign on Monday after a far-right opposition leader won the first round of the presidential election re-run, heightening political uncertainty in the country.

George Simion, leader of the hard-right Alliance for the Unity of Romanians, emerged as the clear frontrunner in Romania ’s presidential election redo, securing 40.5 per cent of the vote with nearly all ballots counted. The vote followed last year’s annulled election marred by allegations of fraud.

Nearly complete electoral data shows that hard-right nationalist George Simion has secured a decisive win in the first round of Romania’s presidential election redo.