In a statement, Enac said Ryanair was "systematically" failing to comply with Italy’s regulations on social distancing.
It also warned it could order the budget carrier to operate at 50% capacity or even suspend its permit to fly to Italy altogether if it did not fully enforce the country’s rules.
Enac also raised concerns about failures to enforce mask wearing by passengers, and to instruct passengers to disembark in an orderly fashion.
Airlines can operate to Italy at full capacity if they ensure social distancing is respected before and after take-off, during boarding and disembarkation, and during any shuttle transfers.