Tottenham Hotspur are taking Olympic chiefs to court over the decision to hand the 2012 stadium to West Ham after the Games, the BBC have reported.
The Olympic Park Legacy Company (OPLC), which picked West Ham as its preferred bidder ahead of Spurs to move into the stadium, confirmed Tottenham is going ahead with a judicial review.
Tottenham told the OPLC of its decision this week, as construction on the Olympic Stadium was completed.
An OPLC spokesman said: "We can confirm that a letter before action in relation to potential judicial review proceedings has been issued.
"The Olympic Park Legacy Company ran a very rigorous and transparent process in its selection of the recommended preferred bidder.
"We have been supported by independent experts in their field in terms of legal, financial, commercial and technical advice.
"We have been consistent, fair, objective and entirely equal in our dealings with the bidders from start to finish.
"We are confident that if these judicial review proceedings are pursued, our approach will be entirely vindicated by the courts."