A key tenant of the Sydney Football Stadium would "not have supported" the venue's rebuild had they known a multi-mode LED "curtain" was not to be included in the final budget.

Acting Sports Minister Geoff Lee on Monday confirmed the NSW government would not foot the bill for the curtain, saying the revised $828 million price of the project was the "final cost".

The budget for the Sydney Football Stadium has increased to $828 million. Credit:NSW government

Told of the government's position, Sydney FC chief executive Danny Townsend said the A-League football club would not have supported the stadium rebuild had the club known the two-mode function to accommodate smaller crowds would not be a feature of the new stadium in Sydney's eastern suburbs.

"Rebuilding a stadium of very similar size, with no different configuration would not have been something that we would have supported," he said. "We supported a project that had a two-mode system, that's what was sold to us, that's what got us really behind it and got us really excited about what our future home looked like."