Deputy Prime Minister Warren Truss said yesterday that Wilton should never have been seriously considered.

"A second Sydney airport at Wilton was never a practical option and it is no surprise that the site was all but ruled out in the latest study on Sydney Airport released in April," Mr Truss said.

"The Wilton study was a distraction to enable the government to put off making a decision about Sydney's airport needs until after the election.

"The site is too far from Sydney, creates huge environmental issues and would never attract the patronage of other options."

Wollondilly Shire Mayor Col Mitchell, a long-time opponent of the Wilton site, said he was pleased to hear it had been ruled out.

"It's certainly a good result for us," Cr Mitchell said.

"I know people will say, 'What about the loss of employment?', but you can be from here to Badgerys in about 30 minutes down the Northern Road.

"It's not going to make any difference there. We have a lot of people working at Mascot now from out in this area."

He said the decision would mean the council could get on with the work of planning the new suburb of Wilton Junction, which would cater for 30,000 people and was next to one of the possible airport sites. Cr Mitchell said the airport issue had been "a political football", with the outgoing government preferring to commission more studies rather than make a decision.

Mr Truss said the decision of the location of the second airport would not be delayed by further studies and the new government would base a decision on major analysis completed last year by state and federal governments.

That analysis backed Badgerys Creek as the site, suggesting that the Royal Australian Air Force base at Richmond could be used in a limited commercial capacity before Badgerys was built.

Mr Truss said this same report suggested there would be constraints on Kingsford Smith Airport's operations as early as 2015 and these would need to be addressed in the Sydney Airport Corporation's forthcoming master plan.

He suggested that newer planes could reduce the number of flights in and out of Kingsford Smith, extending its life-span.

"Today, larger and quieter aircraft carry more people per flight and Boeing's 787 and A330 aircraft will soon replace smaller aircraft on high-density domestic routes," he said.