Polling stations in Romania opened at 0600 UTC on Sunday, with the corruption-tainted left expected to surge back into power just one year after the party's prime minister stepped down in disgrace.

The Social Democrats (PSD) - whose leader, Liviu Dragnea, was convicted of electoral fraud - appears set to win 40 percent of the vote. The center-right National Liberal Party (PNL) and the new Save Romania Union (USR) were expected to receive a combined 35-40 percent.

In 2015 a caretaker government of technocrats took over from the PSD after tens of thousands of people protested against corruption, which they said led to the deaths of 64 people in a nightclub blaze in Bucharest.

Romanians blamed corrupt officials for the tragedy, in which stage pyrotechnicians set fire to acoustic foam in the Colectiv Club, causing a deadly stampede for the only functional emergency exit.

Then-Prime Minister Victor Ponta stepped down, and the National Anti-Corruption Directorate began a massive campaign against bent officials.

"We have brought to justice ministers, senators, lawmakers and other public officials," the agency's head, Codruta Kovesi, told AFP. Her conviction rate is 90 percent.

Tackling corruption is a priority for 95 percent of Romanian voters, a recent survey found, but some groups worry that the PSD will not achieve this.

The anti-corruption purge "disproportionately hit the Romanian left," said Tsveta Petrova, from the Eurasia Group risk consultancy.

"As a result, should a left-led coalition come to power, it will try to slow down this campaign," Petrova said.

Populist campaign

The PSD, which would form a coalition with the Alliance of Liberals and Democrats (ALDE), enjoys wide support from older and rural voters.

"They've always been on our side," said 72-year-old state pensioner and former energy worker Georgeta Croitoru. "My pension ... has helped me worry less and amass no debts."

"I really hope my 1,200 lei (266 euros) pension will rise again," Croitoru said.

Dragnea said he would raise salaries and pensions, slash taxes, build more hospitals, offer faster trains and give every village its own ambulance.

The PNL and the USR both said they supported the continuing rule of caretaker Prime Minister Dacian Ciolos. A PSD Government would install Dragnea as the new leader.

But that could create problems, considering a 2001 law that prevents anyone convicted of a crime from becoming a minister. Dragnea received a suspended two-year jail sentence in April for inflating voter numbers at a July 2012 referendum to impeach former President Traian Basescu.

President Klaus Iohannis also said he would refuse to appoint anyone with legal problems as prime minister, which would exclude Ponta, charged with alleged tax evasion and money laundering.

Pro-European Union

Euroskepticism largely skipped Romania despite a European backlash against austerity campaigns following the 2008 financial crisis.

"Romanian public opinion is one of the most pro-European states, because of a total lack of confidence in domestic institutions and politicians," said Sergiu Miscoiu, political science professor at Babes-Bolyai University in Cluj.

"Salvation comes from abroad, and western Europe has a standard of organization and prosperity Romanians still cannot reach," he said. "Outside of a very small audience, public euroscepticism wouldn't benefit any party."

In total 504 seats are up for re-election in Romania's bicameral Parliament.

aw/jr (AFP, AP, Reuters)