The prospect of a grand coalition between Silvio Berlusconi's Forza Italia (FI) party and the ruling centre-left Democratic Party (PD), envisaged before the vote, is no longer feasible after the two underperformed on election night.

Former Prime Minister Matteo Renzi has resigned as leader of the governing centre-left PD, which performed poorly, taking less than 20 per cent of the vote.

He said the party would not join a coalition with "anti-system forces" and would go into opposition instead.

The results leave the populist Five Star Movement (M5S) and the far-right League party in the driving seat as the country looks to cobble together a government with a working majority.

Here are three possible scenarios.

Right-wing coalition

The coalition formed of far-right groups and Silvio Berlusconi's centre-right FI party took 37 per cent of the vote, the leading bloc in the poll.

In a stinging defeat for Mr Berlusconi, the anti-immigrant League party headed by Matteo Salvini emerged as the strongest movement within the coalition, taking almost 18 per cent of the vote compared to Mr Berlusconi's 14 per cent.

The bloc is short of an absolute majority but, speaking after the vote, Mr Salvini said it had the "right and the duty" to govern the country.

The eurosceptic also staked his claim for leadership saying that the leading party in the coalition should nominate the future premier.  

Five Star alliance

The maverick populist M5S was the night's success story, sweeping Italy's south to become the single leading party in terms of votes.

Founded in 2009, the anti-establishment party has experienced a meteoric rise to prominence, riding on a wave of anger and frustration against Italy's traditional parties.

Its sharp-suited 31-year-old leader Luigi di Maio said he "felt the responsibility to form a government for Italy" after clinching 32 per cent of the vote.

Having previously ruled out forming alliances, Mr Di Maio said the party was ready to open discussions "with all political actors" to help form a majority in parliament.

Given its heated rivalry with the PD and Mr Berlusconi, M5S's most likely ally looked to be the eurosceptic League.

However, Mr Salvini swiftly ruled out the prospect of forming a coalition with the M5S.

"N.O. No, underlined three times," Mr Salvini told reporters.

Stalemate

If there is no clear majority, President Sergio Mattarella could choose to leave in place the current centre-left government of Prime Minister Paolo Gentiloni.

This would allow time to set up a temporary government to reform the electoral law and organise new elections.

But the process would take time as consultations could only start after parliament's newly-elected lawmakers meet for the first time on March 23 to elect speakers of the two houses of parliament.

After a stalemate following Italy's last election in 2013, it took more than two months to form a government.