NSW Premier Gladys Berejiklian is standing by her controversial stadium rebuild project, despite revealing the cost has blown out by almost $100 million.

Key points: New stadium will be ready for the 2022 NRL Grand Final and will cost $828 million, $99 million more than had been forecast

New stadium will be ready for the 2022 NRL Grand Final and will cost $828 million, $99 million more than had been forecast NSW Premier Gladys Berejiklian says the deal with John Holland to rebuild the stadium is the best outcome for taxpayers

NSW Premier Gladys Berejiklian says the deal with John Holland to rebuild the stadium is the best outcome for taxpayers Labor calls the cost of the stadium "extravagant" and says Ms Berejiklian lied to taxpayers

The NSW Government today confirmed John Holland had been awarded a $735 million contract to rebuild the Sydney Football Stadium by 2022.

The project was thrown into chaos earlier this year when the Government announced Lendlease would not complete the project after demolishing the stadium.

The project's price tag is also now $828 million, which is $99 million more than had been forecast.

But Ms Berejiklian remained confident the new deal is the best outcome for taxpayers.

"Yes the cost has increased but can I assure the community that you only build a stadium like this every so often and we need to make sure we get it right," she said.

"I am confident we have got the best price and also I am pleased it will be ready for the 2022 NRL Grand Final."

Ms Berejiklian said the amount included "contingency costs", in case something went wrong.

"We've set money aside for additional costs that could happen during the life of the project, so I'm actually hoping we'll come under what that total figure is," she said.

The cost blowout is at odds with a promise by former Sports Minister John Sidoti, who told the ABC earlier this year that he was confident the winning firm would deliver the project on time and on budget.

"I wouldn't go back to tender if I didn't think we could meet those requirements. I'm very confident we'll meet the budget and those time constraints," he said.

An artist impression of the new Sydney Football Stadium which will be completed in time for the 2022 NRL Grand Final. ( Supplied )

Labor leader Jodi McKay slammed today's announcement, saying the Berejiklian Government had failed voters.

"This is extravagant," she said.

"At a time when we've got the worst bushfires in living memory, the worst drought in living memory, we have a premier that's throwing an extra $100 million at a stadium just because of their incompetence."

Ms McKay said the premier has not been honest with taxpayers.

"The government went to the election saying they would sign one contract for the demolition and for the build. That was a lie," she said.