The door has been left open for Leyton Orient to share the Olympic Stadium with West Ham United on an occasional basis, as work begins on adding an 84-metre roof as part of a £160m conversion project. The West Ham vice‑chair Karren Brady, who led the club's bid to win tenancy and move in time for the 2016‑17 season, also insisted they would fill the 54,000 seats on a regular basis despite admitting that it was becoming "harder and harder" to sell out Upton Park's 35,016 capacity.

After a protracted tender process, West Ham were confirmed in March as the main tenant in the stadium, which will be used for athletics and a range of other sports and concerts in the summer.

The London Legacy Development Corporation's chief executive, Dennis Hone, said that he has agreed to meet Orient's chairman, Barry Hearn, who continues to lobby for a ground‑sharing arrangement despite losing a recent bid for a judicial review.

A House of Lords committee said on Monday that it remained unconvinced that the current plans utilise the stadium to its fullest and its chairman, Lord Harris, told West Ham and Orient to "stop squabbling like children" and urged "occasional" use by Orient to be considered. Hone said that the book remained closed as far as a full groundshare was concerned for the League One club but added there could still be scope for it to use the stadium on an occasional basis for big games.

Hone said: "Mr Hearn's stated position is that they want to look at groundshare. His letter to me reiterates that. It goes further than occasional use and talks about groundshare. We've had two detailed competitions. The process was robust and transparent. We're not going to do anything that reopens those competitions or leads to a rerun."

Pressed on whether Orient could use it occasionally, he said: "Never rule anything out. But in terms of groundshare, we ran a competition and we're not reopening it."

The contractor Balfour Beattie will on Thursday begin taking down the floodlights that marked the east London skyline during the Games and are due to erect a new cantilevered roof by spring 2015, in time for the stadium to be used during the Rugby World Cup in 2015.

"The roof has been designed to create the atmosphere and help with the acoustics that we know are so important in football," said Brady.

Hone said that the use of the stadium for the 2015 London Grand Prix athletics a few months before the Rugby World Cup would be largely dependent on whether the track survived being buried beneath soil and concrete.

The Mondo track on which Usain Bolt and Mo Farah won their medals in 2012 has been covered in order to avoid damage from the cranes required to construct the roof, the retractable seats that will move across the track when the stadium is in football mode and hospitality suites for 3,400.

"If the work was behind or there was damage to the track they would have to make alternative arrangements and they [UK Athletics] are fully aware of that," said Hone.

Brady said there had been a "huge amount of interest from across the world" in naming rights for the stadium, which will be put out to tender in the new year and the proceeds of which will be shared between LLDC and West Ham.

Despite not yet having sold out this Saturday's derby with Chelsea, Brady said she was confident that the new stadium's location and an attractive ticket-pricing model would ensure it would be full. "We have a strategy to do it. We have a policy that football should be affordable to everybody, whether you're a kid for a quid or a top executive who wants all the benefits of hospitality. There should be something for everyone in this stadium."