Failure to meet a looming deadline will not terminate billion-dollar plans to turn a major Australian racecourse into 25,000 homes.
The potential to redevelop western Sydney's prime horse racing venue at Rosehill was unveiled in December as a key plank of the government's solution to the housing crisis.
At the time, state officials agreed to review and help guide the concept developed by track owner Australian Turf Club before it submitted a formal proposal.
The agreement, tendered to parliament on Friday, is set to expire on March 31.
But missing that deadline would not be fatal, MPs were told.
"They are able to present a proposal at any time," Treasurer Daniel Mookhey told a budget estimates hearing.
The agreement to continue state government assistance in developing the proposal could also be extended beyond March 31.
The redevelopment hinges on a station on the $20 billion Metro West line being built underneath the greenfield property.
The ATC has suggested the addition of the station could lift the property's value to as high as $5 billion.
Proceeds would deliver a new training base in western Sydney, a redeveloped Warwick Farm track and investment in stands at Randwick and Canterbury.
But the deal the ATC says will secure racing's future has been treated internally with disgust from high-profile trainers including Gai Waterhouse and Chris Waller.
The NSW treasurer declined to predict how long the process would be open to the ATC.
Asked what would happen if a proposal was never submitted, he said "plan B was to build the metro" and ensure other housing targets were achieved.
But exploring a great opportunity for well-located homes was important, he said.
"To put it in really stark terms, to the best of my recollection, (inner Sydney councils) Woollahra and Mosman between them added perhaps 1100 new dwellings in 10 years," Mr Mookhey said.
But the Rosehill deal appeared "dead on arrival" and was backed by a memorandum of understanding lacking in substance, the opposition said.
"We have with Rosehill another thought bubble from this government, a government addicted to spin over substance," opposition housing spokesman Scott Farlow said.
