Two of the richest regions in northern Italy are heading to the polls to demand greater autonomy from the central government in Rome.

Around 11 million voters in Lombardy and Veneto, nearly a quarter of Italy's population, are casting their ballots on Sunday in a non-binding referendum approved by the constitutional court.

Voters will decide whether they want their regional governments to claim more control from Rome over tax revenues, immigration and education systems.

A resounding "yes" vote will give the neighbouring regions political leverage in negotiations with Rome.

A turnout of more than 50 percent of the eligible voters is required in Veneto for the referendum to hold. There is no quorum for Lombardy voters.

The two regions account for 30 percent of Italy's GDP, but many taxpayers in the north resent subsiding the relatively poor south of Italy.

Italy's twin referendums come on the back of the vote on independence in Catalonia. Tensions have been high in neighbouring Spain after an overwhelming 90 percent voted in favour of secession.

Al Jazeera's Hoda Abdel Hamid, reporting from Veneto's capital, Venice, said: "The Lombardy and Veneto referendums are yet another signal of European separatists movements picking up steam again."

An approval of the parliament will be required to allow regional autonomy.

Meanwhile, some are also in favour of independence.

"Everyone has the right to decide its own administration," Franco Tonello, independence campaigner, told Al Jazeera.

"Our culture has been forgotten. Our children are not taught the history of the Republic of Venice but a history that was never ours."