Leyton Orient chairman Barry Hearn has demanded a judicial review of the Olympic Stadium bid process, saying it denied the club the chance to make an effective case.
Hearn wants League One side Orient to share the east London venue, which is set to be West Ham United's future home after they were named as preferred bidders late last year.
The Brisbane Road chief has begun legal measures to have the decision to allow the Hammers to move into the 60,000-seat stadium thrown out.
He said he believed the London Legacy Development Corporation bidding process did not provide "for teaming, which is for all parties to share the stadium".
"It is our legal opinion that this is a fundamental flaw of the bidding process," he said. "We have gone to the High Court to have the decision struck out."
Hearn said Orient had not been allowed to make a proper case for sharing, which he said was something favoured by many European clubs.
"We have to protect ourselves," he explained. "We are doing everything we can to protect Leyton Orient Football Club, which is endangered by West Ham moving to the stadium."
A statement from the LLDC said: "We have been notified that Leyton Orient have made the decision to issue proceedings for judicial review.
"Whilst this is disappointing, we believe that our processes have been robust, fair and transparent and that the challenge is misconceived."
Hearn said Orient were confident of success in the legal process, but did not know how long it may take for the matter to be resolved.
Orient and Tottenham challenged a 2011 deal for West Ham to move into the Stratford stadium, which then collapsed.
After the LLDC later ranked the Upton Park club as preferred bidders from a shortlist of four, they said a move into the stadium was not a done deal and would not happen until the 2016-17 season or later.
The £249 million stadium would be rented for 25 days a year on a 99-year lease by West Ham, and would also be used for events including the 2017 World Athletics Championships and pop concerts.