Romania's opposition Social Democrat Party (PSD) appeared to have won today's parliamentary election, acording to exit polls, reducing chances for a revival of EU-mandated anti-corruption reforms if it manages to form a government.

The PSD tapped into many Romanians' fears about the impact of the global financial crisis and wealth disparities to make a last-minute comeback after itself suffering sleaze scandals. It promised welfare handouts and tax cuts for the poorest.

Two exit polls, one by private Realitatea TV and one by the public TVR 1, showed the PSD, heirs to Romania's communist regime overthrown in a bloody 1989 revolt, capturing 36-37 per cent of the vote.

Another opposition group, the Democrat Liberal Party (PD-L), a centrist grouping linked to President Traian Basescu, won 30-31 per cent, while Prime Minister Calin Tariceanu's Liberal Party (PNL) was third on 20 per cent.

To form a government, the PSD will have to wrestle with the PD-L, which benefits from close links with the president, who nominates the prime minister under Romanian law.

Today's win boosts its chances of returning to power after four years in opposition; but a coalition between the Democrats and Liberals, who have majority together, is also possible.

"Everybody is going to play hardball so we may see a lot of instability ahead," said Alina Mungiu Pippidi of the Romanian Academic Society think tank.

"There is quite an important chance the PSD will get into the next government. For fighting corruption, the situation is pretty bad," she said.

The PSD government in 2000-2004 was widely accused of allowing corruption to fester. Several of its top politicians have been indicted on graft charges but trials have been blocked by parliament or mired in court proceedings.