Virgin Blue has joined Qantas in urging the Australian Government to move quickly on a second Sydney airport, warning that the existing facility is becoming a bottleneck.

Virgin Blue and other airlines are becoming increasingly vocal about problems at Macquarie Airports-controlled Sydney Airport and the need to start planning for a second facility.

Chief executive Brett Godfrey called on the Government to becourageous and make a decision on where a second airport should go.

He said he did not accept MAp's assertions that there was adequate opportunity to expand Sydney Airport.

"I just feel that's what governments are meant to do, aren't they - take courageous decisions? So someone has to stand up and do it," he said.

"It will (introduce) some competitive tension, it will mean lower airfares, less congestion and it will provide an economic stimulus not just for this state but for travellers."

Mr Godfrey said on-time performance for all airlines had declined 5 to 10 percentage points in the past 18 months as a result of congestion.

He said Sydney - both the airport and air traffic control - were the major culprits as they struggled to handle the volume.

Virgin Blue had already run out of space at Sydney Airport.

"Slots are not the issue, it's actually infrastructure and whether Sydney's got the capacity, as they've alluded to, to be able to meet the demands," he said. "I think they're talking the next decade or 20 years where they believe they have enough, but I don't think they do."

"Their argument is that everyone's just going to be forced into taking bigger aeroplanes and we can't fly big aeroplanes on the facilities we have today."

"There are no category D gates that we can operate from so we can't go with wide-bodies, and why force us into that position?"

Mr Godfrey also confirmed that Virgin Blue had talked with the owners of Bankstown Airport about the possibility of operating its smaller Embraer regional jets from the facility.

He said Bankstown operations would draw on travellers in the vicinity, but he emphasised Virgin Blue was not actively lobbying for the change.

"At the end of the day, if the political will isn't there, we're not interested," he said. "We think there is a consumer will that also should be considered. We have spoken to them and we would be keen, I think it would be a good Embraer market."

Asked where a second airport should go, Mr Godfrey said he had no particular preference other than for something to be done.

"We'll happily support any initiative to build a satellite or ... secondary airport for Sydney," he said. "World cities have them and world cities need them."