Italy's political leaders have started canvassing ideas to drag the country out of its post-election gridlock but forming a stable government looks like a pipe dream broken in the face of self-interest and political convenience.

Democratic party (PD) leader Pier Luigi Bersani opened the door to joining a governing alliance with Beppe Grillo, preferring the comedian to Silvio Berlusconi as his first option but that door was slammed in his face just a few hours later.

"Bersani is a dead man talking," Grillo wrote on his blog. "In the last few days, he has been bothering M5S [Five Star Movement] with indecent proposals instead of resigning as anyone else would have done."

Bersani's leftwing coalition holds the majority in the lower chamber of parliament but is 35 senators short of a majority in the upper house. It holds 123 seats but needs 158.

Under the Italian constitution, a government has to hold both houses. To rule, Bersani has to gain the support of senators in Berlusconi's party (117 seats ) or Grillo's M5S (54) because former prime minister Mario Monti's 19 are not enough.

Berlusconi is reportedly waiting for Bersani to make him an offer to form a PD-PDL government.

They have already been jointly ruling Italy since November 2011, providing Monti's government with parliamentary support.

The media tycoon envisages a new coalition able to function until they can restructure themselves adequately to face the anti-establishment tide tapped by Grillo.

"Bersani should make a real offer," PDL secretary Angelino Alfano said. "They [PD] need to be modest and set aside any bias [against Berlusconi] in front of the electoral result," said Berlusconi's aide Denis Verdini.

But a PD-PDL coalition is seen as political harakiri by some Bersani aides.

An alliance with Berlusconi would play into the hands of Grillo as he has built his platform on public anger at the old ruling class that the two parties represent and their support of Monti's harsh austerity measures.

Bersani tried to play the "responsibility" card to lure Grillo into joining an alliance but it didn't work.

"They [Five Star Movement members] have been saying we should all go home. Now that they are in parliament, they should go home as well or say what they intend to do for this country," Bersani said.

Grillo replied that his MPs would not support Bersani and would back only bills that were in harmony with the Five Star manifesto.

If PD and the PDL formed a government the Five Star Movement would not be tarnished by unpopular decisions taken to beat the economic crisis and could pick up more support from disaffected voters.

"To give back the country to Berlusconi for another six to 12 months is a crime against the galaxy," Grillo said as the count continued.

Beppe Grillo
Five-Star Movement activist and comedian Beppe Grillo (Reuters)