Centre-left leader Romano Prodi looked on course to beat Prime Minister Silvio Berlusconi in Italy's general election, exit polls said on Monday, but initial counting indicated that he had only a narrow lead.
Pollsters said the result could be especially close in the upper house of parliament (Senate), and leaders of the centre-right alliance refused to concede defeat.
Centre-left leaders said they saw clear signs that the nation had nonetheless turned against Berlusconi, punishing him for failing to deliver on promises to revive the lagging economy and slash taxes.
According to an exit poll by the Nexus research institute, Prodi's Union coalition was set to win between 50 and 54 percent of the vote in both the lower and upper houses of parliament, giving it a working majority in the two chambers. Berlusconi's centre-right bloc was shown winning 45 to 49 percent of the vote according to the poll, broadcast by state television RAI after voting ended in the two-day election.
Three hours after polls closed, counting was going slower than expected. Nexus said that based on a sample of 15 percent of the vote in the Senate, the centre-left had won 50.4 percent of ballots cast against 48.6 percent for the centre-right.
This would give Prodi some 158 of the Senate's 315 seats with 151 seats going to Berlusconi and his allies.
The interior ministry indicated that turnout was set to be more than 83 percent against 81.4 percent in 2001. Berlusconi always maintained that a high turnout would benefit him. Official results are due by the end of Monday.