The English Football League insists it has sufficient evidence to charge Sheffield Wednesday with misconduct over the sale of Hillsborough stadium.
Wednesday informed the EFL on Wednesday that the charges were "unlawful" and have threatened to take legal action.
The Sky Bet Championship club have denied all allegations put forward by the EFL after it opened an investigation into the Owls' profitability and sustainability submission for 2017-18.
The club has been reported to have registered a £38million profit from the sale of the stadium to a company owned by their chairman Dejphon Chansiri in the wrong year in order to avoid breaching financial fair play rules.
The EFL had said previously the charges would be considered by an independent disciplinary commission with sanctions possibly including a severe points deduction.
An EFL spokesman said: "As a result of the disciplinary proceedings announced last month, it would clearly be inappropriate to provide specific comment on matters linked to our comprehensive investigation other than to reiterate that, following the review of a large number of documents provided by the club – some of those seen for the first time – evidence came to light to justify multiple charges of misconduct."
The Owls said in a statement on Wednesday that they had informed the EFL that the charges were "unlawful" and had documents to support their claim.
"The club has reserved all of its rights against the EFL and will take all such actions as are necessary to protect its rights and integrity, and those of its current and former officers, including in relation to inaccurate reporting.
"The club has also notified the EFL that it stands ready to bring a claim against the EFL to obtain compensation for its conduct.
"The club maintains that it consulted with the relevant executive officers of the EFL in connection with the stadium transaction and that it acted in good faith.
"The club has in its possession numerous emails, letters and other documents in which the EFL gave authorisation to the transaction, and on which authorisation the club understood it could rely.
"That authorisation gave rise in law to a legitimate expectation that the transaction would be accepted by the EFL, which is binding on the EFL.
"The EFL is acting in breach of that binding legitimate expectation by retrospectively treating as misconduct that which it had itself previously authorised, and this makes the charges themselves unlawful.
"The club is accordingly bringing its own claim against the EFL to establish that it is acting unlawfully, as well as standing ready, if necessary, to vigorously defend the charges."
