The Olympic Delivery Authority and the London Organising Committee of the Olympic Games will not sign off final interior designs for the 2012 Olympic venues until after the Beijing Olympics this year.

This emerged as Carillion was this week understood to have been named preferred bidder on the media centre, with the price tag believed to be about £400m.

The Olympic clients are reserving the right to make changes to “overlay” spaces within the projects, which cover functions including security, back of house operations, catering and signage.

The changes, which would not affect the exterior structures of the venues, would be implemented in the light of any performance issues with venues at the Beijing Olympics, taking place this summer.