Rival populist leaders fought on Monday for the right to govern Italy after their surge in a general election left the country in political limbo.

The anti-immigrant League party and the anti-establishment Five Star Movement (M5S) each claimed Sunday's vote gave them a mandate to lead the nation of 60 million.

League leader Matteo Salvini said that he had "the right and the duty" to form a government after its surprise success at the heart of a right-wing coalition.

But M5S, which won the biggest share of the vote of any single party, claimed it was the winner. Its leader Luigi Di Maio said it had a "responsibility" to form a government.

With most ballots counted, the League was leading the dominant right-wing coalition, which won roughly 37 percent of the vote overall.

The League by itself was closing in on 18 percent, ahead of former prime minister Silvio Berlusconi's Forza Italia (Go Italy) party, which collapsed to 14 percent.