Leyton Orient have begun legal proceedings over West Ham's proposed move to the Olympic Stadium after the 2012 Games.
The League One club have followed Tottenham in seeking permission for a judicial review against Newham Borough Council.
Chairman Barry Hearn claims the Council's decision to loan £40million to the company which will be set up to run the stadium after the Olympics, who will then rent it West Ham, is unlawful.
Hearn fears a Premier League club moving within two miles of their Brisbane Road ground puts their future at risk.
Orient are also planning a judicial review application against the Olympic Park Legacy Company, the Government, the Minister of Sport and the Mayor of London.
Furthermore, they will take action against the Premier League who they feel have ignored their own rules by giving West Ham the go-ahead.
Hearn is clearly in no mood to back down and told Sky Sports News: "The whole plan is that we do not want West Ham in the Olympic Stadium, it is black and white, we think they are on our patch.
"We think various parties have acted unlawfully and illegally and they need to be called to task. We have started today with the official announcement we have submitted for judicial review an application request against Newham Borough Council.
"This is an all-encompassing charge by Leyton Orient, a battle by the little man against the big forces of evil if you like, this represents a challenge to our future and we have no choice but to fight our corner, and we believe we have right on our side."