The support is in stark contrast to a Newspoll taken 16 years ago that found 70 per cent of voters were either opposed or undecided. Prime Minister Tony Abbott is preparing to announce a decision on the second airport, but Mr O’Farrell has called for the federal government to first commit significant funding for a new rail and road package, because NSW was not prepared to foot the bill. Addressing Parliament last week, Mr O’Farrell again said it was ‘‘a matter for the federal government’’, and warned hospital upgrades and the West Connex and Pacific Highway upgrades would be put at risk if the state had to pay for airport infrastructure. NSW Opposition Leader John Robertson announced Labor’s support for an airport at Badgerys Creek a fortnight ago, saying it could transform western Sydney. Fairfax Media on Saturday reported a 15 per cent swing against the O’Farrell government, which puts Labor ahead for the first time since 2008, and puts at risk a swag of western Sydney Liberal seats surrounding Badgerys Creek.

Mrs Davies, on a 12 per cent margin, said there had been a ‘‘significant shift’’ in western Sydney’s views on an airport, and it was likely to reignite as an election issue in 2015 if a decision was made or was imminent. ‘‘Roads in western Sydney are already congested, and will become worse unless they are upgraded,’’ she said. Residents wanted the jobs boost an airport would bring and more convenient access to an airport. They also believed it would bring tourism to the area. The state government needed a ‘‘shopping list of the necessary infrastructure ready and lodged’’, so any announcement by the Abbott government ‘‘is not just an airport in a cow paddock’’, she said. Mr O’Farrell was hearing the same thing from other western Sydney MPs, she said. The Liberal MP for Londonderry, Bart Bassett, said a second airport would be a ‘‘major jobs driver’’ that would bring much needed cross-regional roads and rail links to the west. Mr Bassett’s seat has a narrow 5 per cent margin after a boundary change and he is seeking to move to the neighbouring seat of Hawkesbury.

‘‘Twenty years ago in western Sydney an airport was used as an election scare campaign ... but the area is now a broad mix of professionals and tradespeople and everybody travels by air. They are sick of travelling to Mascot because of the cost and time and traffic clogging the freeways,’’ he said. ‘‘I don’t see anything else on the horizon that would create the jobs that another airport would create.’’ Penrith MP Stuart Ayres, on a 16per cent margin, said the community wanted a decision made. But the Minister Assisting the Premier on Western Sydney said he shared Mr O’Farrell’s caution, and it was a decision for the federal government. ‘‘There might be opportunities associated with jobs development, but there are also social costs such as airport noise,’’ Mr Ayres said. He said until the alignment of runways was known, there would be community unease about noise. ‘‘It needs to be supported by enabling infrastructure, roads and rail, or there is little likelihood of a jobs boom in western Sydney,’’ he said.

The Liberal MP for Camden, Chris Patterson, whose boundary moves to include the airport site at the 2015 election, said he had long opposed an airport at Badgerys Creek, although local businesses supported it. ‘‘The business community is absolutely for it,’’ he said. Mr Patterson said an airport would impact on the thousands of residents who had moved into new housing estates built since the airport site was identified. ‘‘I don’t think the airport is the gift that is touted. But the infrastructure, the roads and rail, that need to come with it, are the gift,’’ he said. The Premier’s office did not want to comment.