Labor would dump a proposed redesign of Sydney’s Circular Quay, including a pedestrian high line along the Cahill Expressway, and simply upgrade the wharves and promenade if it wins the election.

The policy, revealed in costings by the Parliamentary Budget Office, would save $315 million in planning and design costs. But accounting for the cost of the wharf upgrades means the budget would only be $75 million better off over the four-year forward estimates.

The Cahill Walk was a pet project of Premier Dominic Perrottet, whose hatred of the expressway is well known. He said last year that while the road could not be torn down yet, it could be enhanced and turned into “one of the world’s truly great walks”.

The government budgeted $216 million over three years for planning of the Circular Quay renewal scheme, including redesigning the wharves and promenade, upgrading the train station and retail, new green spaces and a pavilion, and the “high line”. It had not yet budgeted for construction and delivery of the project.

In December, the government chose a consortium including Lendlease, Capella Capital and BESIX Watpac as its planning and design partner, and the project team undertook a site investigation in January.

The independent PBO said cancelling the current planning and design process would save $315 million over four years, $140 million of which was from the Restart NSW fund and would need to be reallocated to suitable projects.

Upgrading the wharves and promenade, which are near the end of their working lives, would cost $716 million in total, $240 million of which was over the forward estimates (2022/23 to 2025/26) and another $476 million in the final two years.

“NSW Labor will continue with the upgrades of the promenade and the ferry wharves at Circular Quay after 12 years of neglect by the Liberals and Nationals,” Labor leader Chris Minns said.