Whips Francesco Silvestri and Stefano Patuanelli said the government had used an ordinary law, rather than a Constitutional law, to “undermine the constitutional order” with the so-called ‘Split Italy’ legislation.

The controversial measure, which won final approval in the Lower House on Wednesday, will enable regions to request more power over how the tax revenues collected in their areas are spent.

Opposition parties say it will worsen Italy’s north-south divide as it will favour wealthier regions in the north.

The M5S, the centre-left Democratic Party (PD) and the other opposition groups have said they are going to collect signatures to hold a referendum on abolishing the law.

Deputy Prime Minister and Foreign Minister Antonio Tajani said Thursday that the reform “goes in the right direction” and dismissed charges that it ‘splits Italy’.

He said it had raised “legitimate concerns in the south of the country” but added that these would be dispelled with legislation implementing protections for the south.

ANSA