Portuguese voters are going to the polls in an early election that looks set to produce another vulnerable minority government, just as the country is poised to start spending a huge windfall of European Union funds.

That outcome would leave Portugal back where it started two months ago, when politicians rejected the minority Socialist government’s spending Bill and the country’s president dissolved parliament.

Opinion polls suggest the centre-left Socialists and their main rivals, the centre-right Social Democratic Party, are in a tight race.

The two parties traditionally attract around 70% of the vote and have for decades alternated in power in western Europe’s poorest country.

The landslide victory needed to form a majority government, which can pass most legislation despite opposition in parliament, is rare. Portugal has had just three majority governments in the past half-century.

This means one of the two main parties is likely to have to form parliamentary alliances by cutting deals with smaller parties.

Portuguese Prime Minister and Socialist Party secretary-general Antonio Costa delivers a speech during an election rally in Almada, outside Lisbon (Armando Franca/AP)

The stakes are high: Portugal, which has a population of around 10.3 million, is poised to begin deploying some 45 billion euros (£37.4 billion) of aid as a member of the EU to help spur the economy after the Covid-19 pandemic.

Two-thirds of that sum is intended for public projects, such as major infrastructure, giving the next government a financial bonanza. The other third is to be awarded to private companies.

The ballot is taking place amid a surge in coronavirus cases blamed on the Omicron variant, with about 1.2 million people confined at home but allowed to go to polling stations to cast their vote.

President Marcelo Rebelo de Sousa, in an election-eve address to the nation, urged people to vote, saying it is “a way of saying that … nothing, and nobody, can silence our voice”.

He said the coming years will be marked by “leaving behind a painful pandemic (and) an urgent rebuilding of the economy”.

Since the Socialist Party came to power in 2015, it had relied on the support of its smaller allies in parliament – the Left Bloc and the Portuguese Communist Party – to ensure the annual state budget had enough votes to pass.

But last November their differences, especially over public health spending and workers’ rights, were insurmountable, leaving Socialist Prime Minister Antonio Costa short of votes to pass his party’s plan.

He could seek to resurrect the left-of-centre alliance, despite some acrimonious exchanges during the election campaign.

The Social Democrats, meanwhile, may have to deal with a surge in support for the Chega! (Enough!) populist party, whose policies Social Democratic Party leader Rui Rio finds distasteful.

The Social Democrats have also in the past joined forces with the smaller Popular Party.

Rui Rio, leader of the centre-right Social Democratic Party, on the campaign trail in Lisbon (Armando Franca/AP)

The Socialist Party promises to increase the minimum wage, earned by more than 800,000 people, to 900 euros (£748) a month by 2026. It is currently 705 euros (£586). Low wages are a common grievance among voters.

The Socialists also want to “start a national conversation” about working four days a week instead of five.

The Social Democratic Party is promising income tax cuts and more help for private companies, cutting corporate tax from the current 21% to 17% by 2024.

The winner will also have more deep-rooted problems to address, including an economy that cannot get traction.

Portugal’s economy has been falling behind the rest of the 27-nation EU since 2000, when its real annual gross domestic product per capita was 16,230 euros (£13,490) compared with an EU average of 22,460 (£18,668).

By 2020, Portugal had edged higher to 17,070 euros (£14,188) while the bloc’s average surged to 26,380 euros (£21,927).