The polls have opened in what has been described as one of the most unpredictable general elections in Italy's history.

There are concerns that the vote may fail to produce a clear winner capable of tackling the country's economic problems.

The latest opinion polls put a centre-left coalition led by Pier Luigi Bersani in the lead. 

If his party falls short of the majority it is expected he will form a coalition with former Prime Minister Mario Monti.

Bersani has promised to stick to Monti's budget discipline but says he will do more for growth and jobs to help Italy out of its longest recession in 20 years.

But controversial former prime minister Silvio Berlusconi is likely to be one to watch.