PIER Luigi Bersani, Italy's centre-left leader, has admitted his country is facing "a dramatic situation" after the split vote that threatens prolonged instability and a revival of Europe's financial crisis.
As the inconclusive election result in the EU's fourth largest economy sent markets tumbling, leaders across the continent called for the quick formation of a "stable" government.
Guy Verhofstadt, a Belgian politician and member of the European Parliament, said stability was key "if we want to avoid a return to the worst of the eurozone crisis".
"It is a very difficult result for the EU as a whole," said Martin Schulz, the German Social Democrat president of the European Parliament. "What happens in Italy affects us all."
Mr Bersani had been expected to win a working majority. Though he captured the lower house of parliament, his Democratic Party won only 123 seats in the Senate, nowhere near the absolute majority of 158 required for a clear mandate.
"We are aware that we are in a dramatic situation, we are aware of the risks that Italy faces," said Mr Bersani, in his first speech since the results of the election became known.
Still smarting from the humiliating and unexpected results, Mr Bersani called on Beppe Grillo – a comedian and activist whose anti-establishment Five Star Movement won a quarter of the vote and the most votes of any single party – to participate in some form of coalition.
"Up until now they've said everyone should go home. Now they, too, are on the inside. Either they go home or they say what they want to do with the country," he said.
Mr Grillo said that he had no intention of supporting either the Democratic Party or Silvio Berlusconi's centre-right coalition.
He dismissed the main parties as discredited political dinosaurs who had been swept aside by his movement and were headed for extinction.
"They won't be able to govern," he said. "Whether I'm there or not, they won't be able to govern."
Instead, his movement, known as M5S, will consider parliamentary legislation such as austerity measures and economic reforms on a case-by-case basis, raising the prospect of political instability for months and a possible fresh election.
"The M5S is not allying with anyone, as it has always said," Mr Grillo said on his website.
Mr Bersani instead faced overtures from his nemesis, Mr Berlusconi, to form a grand cross-party coalition, despite the insults and accusations that were flung by the two leaders during the campaign.
"Italy cannot be left ungoverned, we have to reflect," Mr Berlusconi said when asked whether he was open to forming a pact.
The fact that so many Italians voted once again for Mr Berlusconi, despite his sex scandals, corruption trials and clownish reputation, left many people outside Italy aghast. (© Daily Telegraph, London)
Euro stocks tumble as uncertainty over Italy renews fears