New South Wales Opposition Leader John Robertson has written to Australian prime minister Tony Abbott calling for bipartisan support for a second airport in western Sydney.
In a letter to Mr Abbott on Friday, Mr Robertson said western Sydney was facing the major challenges of population growth, jobs deficits and ageing infrastructure.
One way to overcome these was to build a second airport. And after 30 years of debate and more than 50 reports, it was "obvious Badgerys Creek is the only viable site", he wrote.
AAP says Mr Abbott has reportedly put off a cabinet decision to approve a second airport due to political concerns in the city's west.
News Corp Australia reported on Thursday that Mr Abbott will instead establish a committee made up of western Sydney Liberal MPs to report on their concerns about the Badgerys Creek proposal.
In his letter, Mr Robertson argued the government would need to make certain commitments to the community in order for the project to be a success.
This included an assurance that the airport would operate with the same curfew as Kingsford Smith Airport and that passenger flights would be available.
Connections to the South West Rail Link and Sydney Motorway Network as well as extensions on the M4 East and M5 East would also have to be completed before an airport was built.
"If the Federal Government puts forward a fair deal for Western Sydney that meets these conditions I will give it my full support," Mr Robertson said.