Egyptian club Al Ahly says it has appealed to the Court of Arbitration for Sport (Cas) over the decision to host the African Champions League final in the Moroccan city Casablanca.
However, Ahly have protested as Wydad Casablanca could be provided with home advantage if they progress from their semi-final tie.
"This decision will give a home advantage to a certain team that will play at home in front of their fans in addition to violating other laws and regulations," a statement from Al Ahly said.
Al Ahly had asked Caf for a neutral venue before it announced its decision to award the game to Morocco on Monday, but Wydad's home ground - the Mohammed V Stadium - is set to be the venue for the final.
Wydad lead 3-1 over Angola's Petro Atletico, while Al Ahly hold a 4-0 aggregate advantage over Entente Setif of Algeria after the first legs of their respective ties.
The Egyptian Football Association has also voiced its disapproval to Caf and threatened its own legal action "to preserve the rights of Al Ahly".
Cairo-based Ahly, who have won Africa's top continental competition a record 10 times, has said Caf has committed "violations that do not meet the Olympic Charter, Fifa and Caf regulations".
"Al Ahly hopes Caf will be keen not to disrupt justice and will provide Cas with all the required documents that will help in achieving justice," the Al Ahly statement added.
Meanwhile the Egyptian FA has written to Caf to demand a neutral venue, claiming its decision "does not provide equal opportunities for all teams".
"The EFA completely disapproves of the Caf decision to allow Morocco to host the final," a statement said.
"The EFA fully supports Al Ahly in getting their deserved and legal rights in that case. Also, the EFA is willing to take any legal actions in order to preserve the rights of Al Ahly."
Caf's decision has sparked fury in Egypt, with Al Ahly coach Pitso Mosimane leading the way in criticising the decision.
A lack of bidders
BBC Sport Africa understands that when the original deadline for bid submissions passed at the start of the year, only Morocco had come forward to bid.
With the North African nation having hosted last year's final, Caf encouraged other countries to stage the match but, despite expressions of interest from Nigeria, Senegal and South Africa, only Morocco remained when it came to decision time.
With its brand new 50,000-capacity stadium in Diamniadio, Senegal had been considered a serious candidate to win the bid but withdrew last week.
A Caf source told BBC Sport Africa it costs "a significant amount" to host the final and "if it was easy, we'd be discussing candidacies from 10 countries or so".
The African Champions League final was previously decided via a two-legged (home and away) tie, but the format was changed to a one-off match in 2020.
In a possible sign of the difficulties in finding a host nation willing to invest funds in hosting the final, Caf also announced on Monday that talks are underway to revert to a two-legged final.
Casablanca's Mohammed V Stadium also hosted the African Champions League final in 2021.
In a separate development, Caf has announced the Nigerian city of Uyo will stage this year's Confederation Cup final on Friday, 20 May.
Clubs from DR Congo, Libya, Morocco and South Africa remain in Africa's second-tier continental competition.