The Football Association - the client on Norman Foster and HOK Sport's controversial project - is determined to win the contractually agreed £140,000-a-day fee from contractor Multiplex for over-running on the scheme.
Multiplex has admitted that the stadium is going to be months late for its 1 May deadline, with widespread rumours now in circulation that it will not be ready until early 2007.
But the contractor insists that these delays are because of changes to the design that have taken place during the construction phase.
The FA and Wembley National Stadium - another of the client bodies - claim any design changes have been very minor and should not be taken into account.
This dispute will almost certainly end up in court, with architects from both HOK and Fosters expected to give evidence.