The Guardian on Friday reported the NSW government had shelved plans to build a dedicated high-speed rail line between Sydney and Newcastle, after spending close to $100 million on planning the project.
"What you do as a government during the budget period is you make investment decisions based on the plans that you've set out," Premier Dominic Perrottet told reporters on Friday.
However, the premier insisted the government's ultimate goal of creating high-speed rail links across NSW remained intact.
Those projects would be rolled out in an economical way.
"As you move forward, you prioritise your projects in a way that is affordable and sustainable, that sets out the future vision," he said.
"That's what we've done as a government."
The government's two-decade "six cities" strategy includes creating improved transport links between the Illawarra Shoalhaven, Western Parklands, Central River (Parramatta), Eastern Harbour (Sydney city), Central Coast and Lower Hunter regions.
Opposition transport spokeswoman Jo Haylen said the government had revealed a major black hole in their spending plans.
She called on the government to release a report into the feasibility of potential high-speed rail routes carried out by UK rail expert Andrew McNaughton.
The $4.6m fast-rail panel led by Mr McNaughton was announced by Gladys Berejikilian in December 2018.
"Ultimately, the fact is that the Liberals make a lot of promises about infrastructure," Ms Haylen said.
"But we know, after the election, there's only one way that they'll pay for this and that's through privatisation."
The Perrottet government has been spruiking a pro-infrastructure agenda in the lead up to the state election, and has attacked Labor in recent days for winding back business cases for Metro lines connecting western Sydney suburbs to the new western Sydney airport.
The opposition has defended its decision to wind back the Metro lines, citing a growing and unmanageable state deficit.Â