Centre-left leader Pier Luigi Bersani (Reuters)

Italian President Giorgio Napolitano has announced that centre-left leader Pier Luigi Bersani will have the mandate to explore if there are political conditions needed to form the government following the inconclusive February election.

Bersani has until Tuesday to confirm that he has the majority needed in both the lower house and the Senate to form a government. Napolitano said it begins a "decisive phase for the country" and Italy needs a government "with full power".

Bersani has ruled out a coalition with Silvo Berlusconi's centre-right coalition, which finished second. And the political movement founded by comic Beppe Grillo, which finished third, has ruled out supporting any established political force.

If the political gridlock is not resolved, Italy would have to hold a new election.