LISBON: Portuguese will be marking ballots on Sunday in a snap parliamentary election with no clear winner in sight and uncertainty increased by potentially low turnout amid record coronavirus infections.

The government has allowed those infected to leave isolation and cast ballots in person, recommending that they do so in the last hour before polling stations close at 7:00 pm (1900 GMT) and promising "absolute safety" during the vote.

Over a tenth of Portugal's 10 million people are estimated to be isolating because of COVID-19. As in many European countries, infections have spiked lately, stoked by the Omicron variant, although widespread vaccination has kept deaths and hospitalisations lower than in earlier waves.

The election is wide open as the centre-left ruling Socialists have lost much of their lead in opinion polls to the main opposition party, the centre-right Social Democrats, and neither is likely to win a stable majority. Low turnout could make projections unreliable, analysts say.

The vote, called in November after parliament rejected the minority Socialist government's budget bill, is likely to worsen political volatility and could produce a short-lived government, unless one of the main parties manages to cobble together a working alliance, which could be a daunting task.

Instability could complicate Portugal's access to a 16.6-billion-euro ($18.7 billion) package of EU pandemic recovery aid and the successful use of the funds in projects aimed at boosting economic growth in western Europe's poorest country.

"I hope it gets settled and we have a stable government, no more uncertainty," said Paulo Pinto, a 43-year-old car mechanic in Lisbon. "I just hope enough people go and vote, make themselves heard despite COVID."

Pharmacy worker Sofia Mantua, 27, said she felt safe enough as she was preparing to vote using her own pen, disinfectant and a higher-grade face mask than the common surgical one.

"In our day-to-day we also end up crossing paths with infected people so the risk already exists. I don't feel like I'm going to take a greater risk" voting, she said.