Italian clubs joining competitions which have not received authorisation by world and European governing bodies FIFA and UEFA will not be allowed to play in national competitions, the head of Italy's FIGC football federation said.
The move comes after three of Italy's top-flight Serie A clubs, Juventus, AC Milan and Inter Milan, were last week among 12 founding members of a proposed European Super League, which collapsed amid a fierce public backlash.
"Whoever is considering joining a competition which is not authorised by UEFA, FIFA and FIGC will lose its membership", Gabriele Gravina was quoted as saying by Italian news agency ANSA.
A spokesman for FIGC confirmed the remarks, saying clubs joining unauthorised competitions, like the European Super League, will not be allowed to take part in Italy's competitions.
The FIGC council approved a new clause to be inserted into federation rules underlining that clubs registering for national leagues must clearly agree they will not join private, unauthorised competitions, or they will be banned.
The clause also applies to friendly games and tournaments.
The breakaway Super League project, which planned for some of Europe's biggest clubs to leave UEFA competitions but continue playing in national leagues, collapsed within three days amid an outcry from fans, governing bodies and governments.
"Anyone who has interpreted the Super League as a simple act of weakness on the part of some clubs experiencing economic difficulties is wrong," Gravina said.
"At the moment we have no news about who has stayed and who is out. This regulation will be inserted in the national licences and will then be embedded into the code of sporting justice.
"If, by the deadline for applications to the national championships, someone joins up to other private leagues, they are out."