Campaigning ended ahead of the weekend for the first round Sunday of Romanian presidential elections that will choose the head of state to lead the former communist state into the European Union.

During a four-hour debate hosted by public television Friday, the 12 candidates delivered their closing arguments to voters, promising to fight corruption and poverty.

Corruption is a major problem in Romania, and Bucharest is negotiating with the EU over reforms, with improvements in justice and internal affairs at the top of the list. Romania hopes to enter the EU in 2007.

Outgoing Social Democrat Prime Minister Adrian Nastase urged Romanians to vote for a "powerful, European Romania, where everybody will enjoy growing prosperity".

"We are now at a crossroads: we can pick the path of poverty, economic disaster and constant squabbling which were Romania's fate between 1996 and 2000, when a rightist coalition was in power, or we can choose the path of modernization and European integration, Nastase said.

"The choice is in your hands."

His main opponent, Bucharest mayor Traian Basescu, who heads the center-right Justice and Truth (DA) alliance, called on voters to "rid Romania of the mafia-like, corrupt system which has governed it over the past four years".

"The time for change has come," he said.

Nastase, credited with 40 percent support according to the latest voter opinion poll, and Basescu (33 percent) are the two candidates expected to make it to the run-off round scheduled for December 12.

The winner will succeed outgoing president Ion Iliescu, 74, who has been one of the major political figures in post-communist Romania since the fall of former dictator Nicolae Ceausescu in 1989.

In an address to the nation, Iliescu called on Romanians to vote for "social solidarity, equity and equality of chances", an overt reference to the ruling Social Democrats' slogans.

Iliescu, who is stepping down as president but running for the upper house of the legislature, the Senate, under the colours of the PSD (Social Democrats), has been accused by the opposition of taking Nastase's side during the campaign despite the constitution forbidding it.

He also dismissed as "diversions" recent media reports that the PSD interfered in the courts to harass opposition politicians.

The press reports cited alleged party meetings going back to late last year at which top-level officials instructed prosecutors to investigate opposition leaders.

The ballot is not expected to change the key elements of Romania's foreign policy, as both Nastase and Basescu are fervent advocates of Romania joining the EU in 2007, and of maintaining close ties with the United States.

There will also be legislative elections Sunday, with the PSD and DA once again dominating. Each is expected to take between 35-40 percent of the vote, less than needed for a majority in parliament.

The swing party looks to be the Democratic Union of Magyars of Romania (UDMR) which should win five percent of the vote, and has said it will ally itself with the party with the highest total in the election.

Extreme right-wing party Greater Romania, which came second in the previous elections, is expected to garner around 12 percent, but after recent attacks against Nastase, it is unlikely the PSD would have it as an ally.

Nearly 18 million voters are expected at the polls which will open Sunday at 7:00 am (0500 GMT) and will close at 9:00 pm (1900 GMT) local time.