But Prime Minister Tony Abbott said the number of people affected by aircraft noise from the new airport would be a sliver of those affected through inner Sydney.

''On the issue of noise, I don't believe this is going to be anything like the problem at Badgerys that it has been at Mascot,'' Mr Abbott said. ''We are just dealing with far, far fewer people.

''If you look at the noise footprint, some 4000 people live within a Badgerys noise footprint, the equivalent noise footprint at Sydney is 130,000. I just don't think it is going to be anything like the issue at Badgerys that it is elsewhere.''

The suburbs with the highest number of residents most affected by noise from Sydney Airport are Mascot, Eastlakes, Leichhardt, Annandale, Marrickville, Petersham and Stanmore. Official noise contour maps have not been provided for Badgerys Creek since environmental impact statements were prepared in the mid-1990s.

But contour maps drawn up as part of a state government strategy into employment lands in western Sydney show flight paths from a Badgerys Creek airport would be concentrated over land slated to be zoned for industry. The main suburbs likely to be affected by a Badgerys Creek airport, according to these maps, would be Glendale, Luddenham, and Horsley Park.

The Badgerys Creek airport is not expected to reduce noise at Sydney because it will be a supplementary one, not a replacement.