By David Latona and Catarina Demony

LISBON/ESPINHO (Reuters) -Portuguese voters headed to the polls on Sunday, facing a choice between switching to a centre-right government or keeping the centre-left in power, although neither appears to have a path to an outright majority.

The far-right Chega party has been growing in clout and could play a kingmaker role in post-election talks.

Issues dominating the campaign in western Europe's poorest country include a crippling housing crisis, low wages, sagging healthcare and corruption, seen by many as endemic to the mainstream parties.

Polling stations opened at 8 a.m. (0800 GMT) and close at 7 p.m. in mainland Portugal and an hour later on the Azores archipelago.

Turnout at 1 p.m. was 25.21%, slightly up from 23.27% recorded at the same time during the previous election in January 2022, the Interior Ministry said. Results are expected around midnight.

The election, triggered by Socialist Prime Minister Antonio Costa's resignation amid a graft investigation four months ago, pits against each other the two centrist parties - the Socialist Party (PS) and the Social Democratic Party (PSD) - that have alternated in power since the end of a fascist dictatorship five decades ago.

"I hope life gets better than what it is now," 86-year-old Diamantino Vieira told Reuters as he waited to vote at a polling station in the northern city of Espinho, where Luis Montenegro, who is at the helm of the Democratic Alliance (AD) of right-leaning parties, also cast his ballot.

The AD, which comprises Montenegro's PSD and two smaller conservative parties, leads in most opinion polls but could struggle to govern without Chega's support. Montenegro has so far ruled out any deals with the radical populists, who want a government role.

Also in Espinho, Ana Maria, 73, encouraged others to vote to complain about the state of the country, adding: "The people in government...just look at their pockets and care only about themselves. They're useless."

Eduardo Velosa, a 35-year-old bookseller in Lisbon, said the election could mark the beginning of a new political cycle. "Everyone should vote because we have many problems," he added.

The ruling PS, led by Pedro Nuno Santos after Costa's resignation, could attempt a replay of their old alliances with the Left Bloc and the Communists that allowed them to govern between 2015 and 2019, if the combined left gets more than 115 seats in the 230-seat parliament.

Surveys suggest support for Chega's anti-establishment message, its vow to sweep away corruption and hostility to what it sees as "excessive" immigration, has roughly doubled since the 2022 election, though it remains in third place.

On Friday, conservative President Marcelo Rebelo de Sousa told Expresso newspaper he would do everything he can to prevent Chega from gaining power, drawing criticism as the head of state is mandated to remain neutral.

Political scientist Antonio Costa Pinto of Lisbon University said Portugal "has entered the dynamic of many European democracies", in which the centre-right is challenged by having a radical party to its right consolidated in third place.

A potential AD minority government, even supported by the smaller centre-right Liberal Initiative, would likely need votes from Chega to pass legislation, making it relatively fragile as Chega could topple it at any point.

However, "a PS victory with an absolute right-wing majority in parliament would be the most complex, most unstable scenario," Costa Pinto added.

More than 10 million citizens are eligible to vote.