ROME — Widespread publicity around primary elections helped lift Italy's center-left Democratic Party to its highest approval rating in nearly two years, putting it in an even stronger position ahead of a national vote, a poll showed on Tuesday.

The Democratic Party (PD), the dominant movement in a center-left bloc, now looks set to lead the next government after the national vote expected in March.

It, along with the center-right, is currently backing the technocrat government of Prime Minister Mario Monti, which has no political affiliation and took office a year ago to stop Italy slipping into a Greek-style economic crisis.

The poll by the EMG research group for the private La7 television network showed the PD would win more than 34.6 percent of the vote if national elections were held now, compared to 15.2 percent for former Prime Minister Silvio Berlusconi's PDL party.

Support for the PD rose by 4.3 percentage points in the week before a run-off center-left primary election on Sunday which put PD leader Pier Luigi Bersani in the front seat to take over from Monti.

The American-style primaries to choose candidates to become the next prime minister were a relatively new experience in Italy.

"There was certainly a 'primary effect' in these results. The enormous television coverage and the closely watched debates were very significant in forming people's opinion," said EMG pollster Fabrizio Masia.

The People of Freedom (PDL) is in chaos, mainly because of Berlusconi's indecision over whether to stand in the election, and has been pushed into third place in the polls by the rampant anti-establishment 5-Star Movement of comedian Beppe Grillo.

The leftist SEL party — which backed Bersani in the run-off primaries against dynamic PD upstart Matteo Renzi, the mayor of Florence — would get about six percent, the poll showed.

Together with smaller parties, the center-left block would win 42.4 percent of the vote, compared to 23.5 percent for the combined center-right, which had dropped 1.6 percent in a week, EMG said.

The latest poll result would give the center-left a good parliamentary majority both under the current electoral law and new voting rules being debated in parliament.

BERLUSCONI PARTY IN DISARRAY

Grillo's 5-Star Movement polled 16.3 in the survey, slightly down on its previous rating. The movement, which has exploited public disgust over a series of political corruption scandals, was holding its own online vote on Tuesday to choose parliamentary candidates for the election.

Berlusconi's party is divided over whether it should hold its own primaries to gain the same boost enjoyed by the center-left after its polls.

Debates between the center-left candidates attracted record television ratings and rekindled public interest in the traditional political system, which is under a dangerous threat from Grillo.

Fabrizio Cicchitto, head of Berlusconi's PDL party in the lower house, who wants to hold primaries, told reporters: "We have paid and will continue to pay for this political void".

Berlusconi, who has swung from praising Monti to threatening to bring down his government, has repeatedly changed his mind in the last few weeks on whether he will stand in the election.

Some analysts say Bersani's victory might spur Berlusconi to get back into the game, giving him the chance to revive his favourite line that the center-left are dangerous communists.

Grillo's populist movement on Monday began a four-day online election for its candidates in next spring's election. On his blog Grillo said only individuals could vote and any campaign groups or committees would be banned in line with the movement's determination to break with conventional politics.

Grillo is famous for his popular online and public rants against establishment politicians who he calls "zombies". He calls Monti "Rigor Montis" and wants a referendum on Italy's membership of the euro.