Michael Daley has accused the NSW government of "bullying" the parliamentary budget office into re-examining its costing of Labor's stadiums policy on the eve of the state election.

The PBO is reportedly seeking independent advice over the costing of Mr Daley’s plan to make the SCG Trust take out a loan to refurbish Allianz Stadium.

The state opposition claims it will come at no cost to taxpayers, compared to the coalition’s $730 million plan to knock down and rebuild the venue.

In its election policy costing published on Monday, the PBO said the concessional loan will improve NSW’s budget position by $685 million over four years.

But the government has questioned whether the policy would harm Labor’s projected surplus, The Daily Telegraph reported on Friday.

Mr Daley labelled it a “furphy”, saying the PBO was independent and had done its costing with Treasury – which has known about the policy since January.

“They didn’t raise any objection,” he told ABC’s AM program on Friday.

“In the last 24 hours, the premier’s office and the treasurer’s office are monstering, bullying, the parliamentary budget office to get them to change their costing.”

He said he has faith in Parliamentary Budget Officer Stephen Bartos and his independence, but “not this last-minute screaming and tantrum throwing by the government because they know their stadium policy is a stinker”.