Leyton Orient chairman Barry Hearn is considering moving the club to a new home on the 2012 Olympic Park.
Hearn has opposed the decision to name West Ham as preferred bidders to move into the Olympic Stadium, and has written to the likes of Prime Minister David Cameron and Mayor of London Boris Johnson to express his objections.
He has also been looking for answers from the Premier League, who would have to ratify West Ham's plans to move grounds.
Orient are the club closest to the Olympic Stadium site, and Hearn believe their existence would be threatened by the arrival of the Hammers.
He has threatened to take legal action if Orient are allowed to suffer from the existence of a Premier League club on their doorstep.
But Hearn said a meeting with Waltham Forest Council leader Chris Robbins has given him encouragement, after learning the club can count on their support and want to keep Orient in the borough.
"For the first time I actually felt a glimmer of hope," Hearn told The Guardian.
"It was totally their idea. They don't want to lose us. In a way the benefits of this FA Cup run have crystallised their thinking on what's important to their community. At the moment I'm keeping all my options open - and threatening to sue everybody."
Hearn said the council had proposed Orient looking at land for a new home on the Eton Manor site, which has been redeveloped for the Olympics.
"We talked about making some kind of presentation to the OPLC - saying there might be a deal to build a new stadium, the Olympic Community Stadium, where I would bring Orient and, also, I think, Saracens Rugby Club, because they're good friends of mine and they're very keen to move," Hearn said.
Under such a plan, Orient would sell their Brisbane Road home, owned by veteran sports promoter Hearn, and invest profits from that deal into building the new stadium.
Hearn says the additional funds required for the stadium would have to be found without relying on the tax-payer.
He added: "Let's have a planning meeting with everyone and say: 'Can this work? Let's make a proper business proposal.' I think the Premier League would help as well but everyone must sit down. And let's not do anything in haste. Otherwise, the legal process kicks in."