'Botched' Sydney bridge cost $38 million

The NSW government's handling of a controversial Sydney footbridge has come under fire after the Auditor-General found it cost taxpayers more than double its proposed cost.

The Albert `Tibby' Cotter Walkway, designed to connect sporting fans to the Sydney Football Stadium and SCG, ballooned to an estimated $38 million following an original estimate of $15 million, an Auditor-General report found.

The report found the blow out in costs was because the project was fast tracked to be ready for this year's Cricket World Cup without any "compelling economic or financial analysis".

Roads Minister Duncan Gay has dismissed suggestions the tweaked deadline was responsible for the cost blow-out.

Instead he has accused the state's Heritage Council of trying to derail the project with a series of delays and scope changes he says set the budget back $10.6 million.

"We are in disagreement with a number of claims made by the auditor-general," Mr Gay told the NSW upper house during question time on Thursday.

"The deadline was achievable within the original budget.

"Design changes were requested by the heritage council on a number of occasions and each time, approval was delayed. It's fair to say they loaded up the project with extra changes and costs to stop it happening."

In one case the heritage council demanded plans be adjusted to shift the bridge's piers a mere 80 centimetres sideways, Mr Gay said.