The Premier League is reportedly facing a legal battle over changes to rules which would prevent clubs from signing commercial deals at inflated prices.
Associated-party transaction (APT) rules are aimed at ensuring a level-playing field across English clubs.
Clubs signing commercial deals at inflated prices would allow them to spend higher sums of money on players.
Sky News have reported that the 20 top-flight clubs were notified on Thursday that one of them are threatening to initiate arbitration proceedings to prevent the changes being adopted.
It's claimed that the club in question is Manchester City, who are already facing a legal battle over 115 charges of breaching Financial Fair Play rules.
They are said to have objected to reforms and have told the Premier League that the changes were 'unlawful'.
Related-party deals has become a big topic in football, due to the state-ownership of Premier League sides Man City and Newcastle.
A source told Sky Sports : 'The whole point of the APT rules is to prevent clubs inflating revenues above fair market value by orchestrating transactions with parties with common ownership.
'Any attempt to block those is self-absorbed and will ultimately damage the game.'
The Premier League is said to be confident that the reforms are permissible after receiving legal advice.
Man City are part of the City Football Group which has a widespread network of clubs, including the likes of Girona, Palermo, Mumbai City, Japanese side Yokohama F. Marinos and Melbourne City.
The reigning champions and Newcastle were two of eight Premier League clubs who blocked a proposed ban on related-party loans - therefore allowing players to move between clubs who have the same owner.
The other six sides who rejected the ban included Saudi-owned Sheffield United, Chelsea, Wolves, Everton, Burnley and Nottingham Forest. The majority of which are part of multi-club empires.
The 115 FFP charges brought against Manchester City were brought a year ago.
Premier League chief executive, Richard Masters, told MPs last month that a date had been set for a hearing on the allegations - though did not state when that would be.