Portugal election: who are the key players and what is at stake?

Who are the key players?

Costa was succeeded in December as head of the ruling Socialist party (PS) by the head of the party's left wing, Pedro Nuno Santos. A former infrastructure minister, Nuno Santos, 46, was a vital link to far-left parties that had supported a previous Costa minority government but which opposed the 2022 state budget, triggering the last general election.

He resigned his ministerial post in late 2022 in a scandal involving a €500,000 severance payment by Portugal's state-owned airline TAP, which was in the middle of a restructuring plan.

The leader of the rival centre-right Social Democratic party (PSD), Luís Montenegro, 51, led its parliamentary group when the party was in government between 2011 and 2015 and imposed severe austerity measures.

An MP for more than 20 years, his refusal to entertain an alliance with the far right led him to break with the prime minister of that period, Pedro Passos Coelho. He was elected head of the PSD in May 2022 at his second attempt.

André Ventura, 41, is a former television sports commentator who initially entered politics in the ranks of the PSD and first grabbed the nation's attention when as a candidate for mayor in a town outside Lisbon he denounced the Roma community.

He left PSD to launch Chega (Enough) in 2019 and has since propounded a populist, anti-establishment message that has found a fast-growing audience. Chega scored 1.3% of votes in 2019's election and 7.3% in 2022, when it finished third.

Political opponents accuse Chega of frequently resorting to xenophobia, racism and demagoguery. Ventura says his party "touches on issues that interest people".

What are the issues?

Corruption ranks high among voter concerns and is a key focus of the far right's campaign. One Chega billboard reads: "Portugal needs cleaning out."

Besides the investigation that triggered this election, another former Socialist prime minister, José Sócrates, is to stand trial over allegations that he pocketed about €34m (£29m) during his time in power from graft, fraud and money laundering.

The PSD also faces corruption allegations, with two prominent party politicians recently forced to resign amid a graft investigation in Madeira.

A housing crisis (housing costs have soared during the Socialists' eight years in government), persistent low pay levels and unreliable public health services are other areas where the records of the two main parties are being challenged.

Besides alleged corruption, Chega is campaigning on the kind of issues that have brought the far right electoral and polling success elsewhere in Europe in recent years: immigration, the climate crisis and culture war battles.

The PS is promising industrial investment but mainly warning that a vote for anyone else risks letting the far right into power - a strategy that worked for Costa in 2022 when the party won an absolute majority but that does not seem so successful this time round.

Who will form the next government?

That's anyone's guess. Polls put the PSD ahead on about 31% of the vote, just above the PS on 29%. Chega lies in third position on about 18%, with half a dozen smaller parties from left and right projected to score between 1% and 6%.

The PSD has linked up with the small conservative CDS-PP party to form Aliança Democratica (AD), and if joined by the pro-business Liberal Initiative (IL) it could have a majority with the backing of Chega.

The centre-right party, however, has ruled out an alliance with Chega, which insists it will only support a rightwing government if it is formally part of a coalition. Ventura has suggested that any political instability after the elections would be PSD's fault.

On the left, the PS - which says it will not block a minority rightwing government if the would be participants finish first but without a majority - would aim to forge alliances with the Communist party (PCP-PEV, on 2%) or the Left Bloc (BE, 4%), led by Mariana Mortágua.

As things stand, though, neither right nor left has an obvious route to a majority - although after eight years in opposition, analysts suspect the PSD might be tempted to ditch its pledge not to work with Chega if a deal would return it to power.

Why does it matter?

Portugal, which in April celebrates half a century since its 1974 Carnation Revolution ended almost as many years of authoritarian rule, has so far escaped the rising influence of the far right seen in other EU member states from Finland to Italy.

Chega chemical castration for repeat rapists and wants zero tolerance for irregular immigration. It has also said it wants Portugal to have more freedom from the EU to pursue some bilateral economic ties.

A strong showing by the far-right party would mark the end of a Portuguese exception. Far-right populists are in ruling coalitions in Italy and Finland and propping up a rightwing government in Sweden.

Despite setbacks last year in elections in Spain and Poland, a far-right party is on track to win this autumn in Austria, while Germany's AfD - although slipping since a recent "mass deportation" scandal - and France's National Rally (RN) are at polling highs.

In European parliament elections in June, radical-right parties are on course to finish first in nine countries including Austria, France and Poland, and second or third in another nine including Germany, Spain, Portugal and Sweden.