The idea of placing an overnight curfew on flights at Sydney's new $6 billion-plus airport at Badgerys Creek should be "dead and buried", Western Sydney Minister Stuart Ayres says.

With a week to go before Sydney Airport has to reveal whether it will take up its "right of first refusal" to build and operate the new airport, Mr Ayres said imposing a curfew would place in jeopardy the success of Western Sydney Airport.

"The airport simply won't work [with a curfew]," Mr Ayres said.

Mr Ayres, the Liberal MP for Penrith, said a curfew for seven hours of the day would stymie its ability to attract international flights because they had to be timed to suit slot-constrained airports around the world.