The English Football Association (EFA) is taking steps to prevent breakaway leagues, such as the failed European Super League (ESL) move, from being pursued in the future.
The EFA has opened an inquiry into the Super League rebellion and sought evidence from the six English clubs involved in the breakaway that could lead to punishments.
England’s top-flight competition, The Premier League, also disclosed Monday it had prepared measures to stop teams playing in closed competitions.
Arsenal, Chelsea, Liverpool, Manchester United, Manchester City and Tottenham formerly dubbed ‘the big six’, launched an ill-fated defection attempt two weeks ago. The clubs aimed to found a new European competition with Spanish clubs Barcelona, Real Madrid and Atlético Madrid, and Italy's Juventus, Inter Milan and AC Milan.
The project imploded after fan outrage, and threats from the British government of legislation being introduced to stop the Super League.
The FA said it is focused on "preventing it from happening, both now and in the future.”
It said it has been working with the government to legislate against similar threats and protect the English football pyramid.
The FA said in a statement:
"Last week, we started an official inquiry into the formation of the European Super League and the involvement of the six English clubs.
"Once we have the required information, we will consider what appropriate steps to take.
"Clearly what happened was unacceptable and could have caused great harm to clubs at every level of English football."
The Super League would have been a largely closed competition with 15 founding clubs guaranteed entry every season without having to qualify.
The Premier League said it has prepared a series of measures to enshrine the core principles of the professional game: an open pyramid, progression through sporting merit and the highest standards of sporting integrity.
They include making club owners sign a charter "committing them to the core principles of the Premier League" with breaches leading to "significant sanctions."
Anger over the rebellion has seen protests in recent weeks at Chelsea, Arsenal and, on Sunday, at Manchester United leading to their game against Liverpool being postponed.
"The fans have played a vital and impactful role in helping to stop the European Super League from happening, and we understand their frustrations," the league said.