West Ham, favourites to move into the Olympic Stadium, plan to convert it into a multi-purpose venue with retractable seating covering the running track during football matches and pop concerts, sources have told ESPN.
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That means the stadium would be able to hold 100,000 for certain events, and the Hammers propose to make thousands of football tickets available for sensible prices.
The East Londoners want to leave their Upton Park home and move to nearby Stratford. They have offered £10 million a year for a 99-year lease, and a decision on the stadium's future is likely to be made by the London Legacy Development Corporation in October.
An insider told ESPN: "There would be surgery to the existing structure to make it a multi-purpose stadium, with retractable seating over the track for football and pop concerts.
"Events being held there, from the football to pop concerts, will be able to hold anything between 60,000 to 100,000 people depending on the event and the interest.
"This will be the legacy for West Ham but also for the community of East London. They believe their bid is the best one in terms of legacy, having a stadium that will fund itself, create thousands of jobs and attract tourists to East London."
The insider said the extra capacity would allow West Ham to charge lower prices and added: "The club would price tickets so everybody could afford to come, and could even give away tens of thousands of tickets to the local community."
West Ham's East London near-neighbours Leyton Orient had threatened legal action over the club's stadium move, fearing it could threaten their existence.
The Os have made a shared use bid, while owner Barry Hearn is reported to have put any legal action on hold until after the stadium decision is made.
Hammers manager Sam Allardyce has said he believes moving to the Olympic Stadium will give the club a chance of breaking into the Premier League elite, describing the possible move as "a dream".
West Ham United have refused to comment on the reports.