Leyton Orient are attempting to prevent West Ham United from moving into the Olympic Stadium by appealing to the High Court.
The League One outfit, who have proposed a ground-share with the Hammers, have applied for a judicial review on the basis that the bidding process involving the Premier League club was "flawed".
"We believe that the bidding process is fundamentally flawed," Orient chairman Barry Hearn told Sky Sports News. "The London Legacy Development Corporation have not followed their own rules when they set out the bidding process.
"All parties involved in the bidding process signed up to the principal of teaming and yet our bid has been turned down without consideration of teaming ie a ground-share with West Ham."
A Legacy Corporation spokesperson 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."
Meanwhile, Hammers co-owner David Gold claimed on Monday that he believed that the former Championship outfit were "close" to securing the ground.
