Tottenham are to take the Olympic Park Legacy Company (OPLC) to court over its decision to award the Olympic Stadium to West Ham.
West Ham were named the preferred bidders for the site in Stratford last month as their proposal was deemed the best fit for the OPLC's criteria, with Tottenham planning to rebuild the Olympic Stadium as a football ground.
Spurs, though, are now challenging the OPLC's process. Judicial reviews allow for challenges on the grounds of illegality, irrationality and unfairness.
An OPLC spokeswoman 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."
She added: "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."