Italian teams who agree to join unauthorised competitions such as the Super League will be banned from competing in Serie A, Italian football federation (FIGC) chief Gabriele Gravina has warned.
Juventus, Inter and AC Milan were among the founding members of the competition which was announced over a week ago.
The plot to create the Super League to compete with the Champions League fell apart rapidly, as several teams reversed their decision to join following threats from football associations and protests from fans.
What has been said?
The FIGC has adopted a new clause into its rules threatening clubs registering for tournaments not authorised by football's official governing bodies that they face expulsion from Serie A and the Coppa Italia.
"As for the anti-Super League rule, whoever is considering joining a competition which is not authorised by UEFA, FIFA and FIGC will lose their membership," Gravina said at a news conference.
"Anyone who has interpreted the Super League as an act of simple weakness on the part of some companies experiencing economic difficulties, is wrong.
"At the moment we have no news of who stayed and who left the Super League. This rule will be included in the national licenses and then it will be embedded in the sports justice code.
"If, by the deadline for applications for national championships, a team joins other championships of a private nature, they are out [of FIGC competitions]."
Gravina in agreement with Ceferin and Boris Johnson
Gravina said he has spoken with UEFA president Aleksander Ceferin about how to deal with the threat of the Super League and says the two chiefs are on the same page.
He was also impressed by UK prime minister Boris Johnson's reaction after he said the Super League would be unfair to fans.
"I was in Montreux, I arrived with Ceferin and we had a very open, fair and concrete discussion on the Super League," Gravina said.
"We immediately found ourselves in tune, I was struck by his great determination and willingness to involve all the political forces on the field. In the space of a few hours we have been good at involving all the political forces concerned.
"The English prime minister was impeccable. He appealed to the fans and not to the clubs. This is an important message."
Have Italian teams quit the Super League?
Juventus president Andrea Agnelli was a driving force in the plot to create the new competition.
Juve said they are "committed" to the tournament but are aware that it cannot go ahead as planned, while Milan sporting director Paolo Maldini apologised to fans for his side's role in the debacle.
But neither side has confirmed that they are pulling out, whereas Inter released a statement announcing they would be withdrawing from the league.