“The negotiation was done without competitive process … giving the CVC fund over 20% annual returns,” Real said in a statement, adding that the operation’s structure was “deceitful” and would expropriate the clubs of a portion of their audiovisual rights over the next 50 years.

The club considers the deal, under which CVC will invest US$3.2 billion in La Liga in exchange for 10% of its revenue and a 10% stake in most of its business, to be a misappropriation of assets generated by Real and will sue La Liga accordingly, Spanish outlet El Independiente reported.

CVC did not respond to a request for comment.

“Legal moves by Real don’t worry us,” a La Liga spokesman said, noting legal battles between La Liga and Real were common. “We have been and are at odds over many topics … there are many open cases between La Liga and the club.”

Relations between Real and La Liga, which have often been strained, hit new lows earlier this year after the club spearheaded a movement to create a breakaway European Super League with 11 other major teams.

The Spanish football league’s Executive Committee, which includes the bosses of Atletico Madrid and Sevilla but not those of Real or FC Barcelona, approved the planned CVC deal on Wednesday and it will now be put to a vote by all league members.

Real said they would call an assembly of their partners to debate the agreement and discuss the “unprecedented patrimonial losses”.

The rejection of the proposed cash injection to La Liga came on the same day that arch-rivals Barcelona announced that star forward Lionel Messi would leave the club.

The Catalans cited the league’s financial constraints as the sole reason as to why the Argentine would be departing Camp Nou after 18 years following the expiry of his deal at the end of June.

When contacted by Reuters about the CVC proposal, which local media reports had suggested would help get Messi’s contract over the line, Barcelona declined to comment.