In a bid to spur economic growth, the then Italian Prime Minister Mario Monti liberalized Sunday trading in 2012, despite pressure from the Roman Catholic Church and unions who said the country needed to keep its traditional day of rest.
"This liberalization is in fact destroying Italian families," said Di Maio, who is head of the anti-establishment 5-Star Movement. "We need to start limiting opening and closing times again," he told reporters.
Earlier this year, Poland restricted Sunday shopping as the conservative government in Warsaw pushed ahead with what it said was a return to Roman Catholic values.
The Italian and Polish initiatives run against a slow liberalization of Sunday shopping hours throughout Europe, where retailers face pressure from a boom in online shopping.
Small shopkeepers in Italy have long sought to overturn Monti's reform, saying their businesses face unfair competition from the big malls.
Di Maio said that larger stores would also have to close on national holidays.
(Reporting by Crispian Balmer; Editing by Kirsten Donovan)