Italians go to the polls on Sunday in a vote that could bring political gridlock after an election campaign marked by anger over the listless economy, high unemployment and immigration.
Pollsters predict that former prime minister Silvio Berlusconi and his far-right allies will emerge as the largest bloc in parliament, but fall short of a majority.
The anti-establishment 5-Star Movement looks set to be the biggest single party, feeding off discontent over entrenched corruption and growing poverty, while the ruling centre-left Democratic Party (PD) is seen limping home in third place.
“There was momentum for 5-Star in the final days of the campaign, but it is hard to see any party or coalition getting the 40 per cent needed to form a government,” said Lorenzo Pregliasco, co-founder of YouTrend pollsters.
Heavily indebted Italy is the third largest economy in the 19-member euro zone and although investors have been sanguine ahead of the ballot, prolonged political stalemate could reawaken the threat of market instability, reports Reuters.
Polling stations will remain open from 7.00 am to 11.00 pm (0600-2200 GMT), with exit polls due immediately afterwards.
The vote is being held under a complex new electoral law which means the final result might not be clear until late Monday.
The campaign has marked the return to frontline politics of Berlusconi, 81, who was forced to quit as prime minister in 2011 at the height of a sovereign debt crisis and was widely written off following sex scandals, legal woes and ill health.
A 2013 conviction for tax fraud means he cannot hold public office and he has put forward Antonio Tajani, the president of the European Parliament, as his candidate for prime minister.