Iris Capital is seeking a review of a state planning panel decision to reject the final stages of its EastEnd apartments development.
The move comes a month after the Hunter Central Coast Regional Planning Panel decided unanimously to knock back Iris's amended proposal for stages three and four of the massive Hunter Street Mall redevelopment, despite Newcastle council support for the project.
Iris warned after the decision that the refusal could leave Newcastle's city centre with "a hoarded-up hole in the ground for years to come".
The panel ruled the proposed $145 million development had an "unacceptable" impact on views and parking and differed too greatly from a concept plan approved in 2018.
A Hunter Central Coast Regional Planning Panel assessment team with different members to the original panel will decide on the review application.
Iris's decision to change elements of its approved 2017 concept plan drew sharp criticism from Heritage NSW, the National Trust, the Newcastle Club, Anglican Dean Katherine Bowyer, Newcastle East Residents Group and Newcastle Inner City Residents Alliance.
Iris said in May that the planning panel's decision had made a mockery of government goals to boost housing supply and improve building design.
"It would be an incredibly disappointing outcome if this significant rejuvenation project were to stall at the halfway point with a key node of the Newcastle City Centre being left as a hoarded-up hole in the ground for years to come," the company said.
The Iris plans changed when City of Newcastle demolished its King Street car park in 2021 over concerns it was structurally unsound.
The developer applied to "remass" stages three and four of the EastEnd complex by adding height and floor space to some apartment buildings in return for creating a public plaza off Hunter Street.
The council last year approved the demolition of buildings on the site, including an old timber house the National Trust classed as an important part of the city's heritage.