Cardiff City's main financial backers have initiated legal proceedings against the club over claims they have not repaid more than £30m in debts.
Law firm Hextalls LLP, on behalf of Cardiff backers Langston, have accused the club's board of mismanaging their finances and misleading supporters.
Cardiff Council has expressed confidence the stadium development will go ahead as money for that is banked.
Meanwhile, Cardiff City chairman Peter Ridsdale has rejected the allegations.
Ridsdale said: "The statements released by Hextalls LLP seem to be an ill-informed mixture of fiction and general confusion."
The Hextalls LLP's statement released on Tuesday evening read: "Our client's claim is that this sum is due for payment now as a result of the club's inability to meet certain deadlines as well as breaching the terms of its loan agreement in respect of the capital sum plus interest.
"It had been hoped to resolve the matter privately and in confidence but the club has repeatedly ignored numerous requests to discuss the debt and its implications.
"As a result of legal proceedings commencing, the issues have now become public and therefore this statement is being made.
"The court action is being taken reluctantly but our client has been left with no alternative following the club's failure to respond to repeated approaches."
On Wednesday, Cardiff Council said it was seeking clarification from all the parties involved and was therefore unable to comment further.
But in a statement, the council added: "The money from the disposal of the retail park is in the bank so the revenue necessary to build the two stadia (the new Cardiff stadium and the city's athletics ground) is in place which is the primary concern of Cardiff Council."