The Hills mayor Michelle Byrne and deputy mayor Andrew Jefferies said mayors, councillors and federal and state members who oppose a second airport were standing in the way of progress and future prosperity.
"We've had more than 30 years of talking," Cr Byrne said.
"I urge the Prime Minister Tony Abbott to be decisive on this issue and help get Sydney moving."
Cr Jefferies said a second airport would deliver unprecedented employment and an economic boost for western Sydney, NSW and Australia.
Cr Byrne said the 1.1 million more people who would call Sydney home over the next two decades would not be adequately served by one airport.