It would be a "disaster for Dubbo and similar regional cities" if it lost its connection into Sydney's central business district (CBD), vital for both medical and business purposes, he said.

Cr Shields renewed his warnings and call for action yesterday after attending the Australian Airports Association's national conference.

He said he would talk to councillors about formalising a taskforce to push to retain legislation that currently protects slots for regional areas into Kingsford Smith Airport at Mascot.

It comes seven months after the federal government announced Badgerys Creek as the site for a second major airport at Sydney, that construction work on the $2.5 billion project was set to begin in 2016 and that the first flight was expected in the mid-2020s.

Cr Shields acknowledged the current legislation but urged regional areas not to be complacent.

"The last few days at the... conference has only strengthened my belief that regional NSW needs to prepare for moves to shift regional flights to the new Badgerys Creek airport," he said.

"It would be a disaster for Dubbo and similar regional cities and towns to have access to their medical and business services so far out of the Sydney CBD.

"Right now, we are protected by a legislated slot system where a certain amount of flights flying into Kingsford Smith Airport must be regional flights.

"However, an airport makes more money with larger aircraft.

"It is obvious the owners of Kingsford Smith will put pressure on the federal government to change the system and send the less profitable regional flights to Badgerys Creek once that airport is built and operating.

"I will be consulting with councillors in the coming days about formalising a regional taskforce to begin the political pressure on the federal government to keep regional flights at Kingsford Smith."

Cr Shields said he supported Badgerys Creek Airport as "essential for Sydney and NSW".

"However, regional flights must remain at Kingsford Smith," he said.

"It's better if we start our argument now before any formal decision is made so we are not caught on the back foot.

"Let there be no confusion.

"All sorts of people will be disadvantaged by regional flights going to Badgerys Creek.

"From people going to medical appointments, right through to specialists and business people coming to Dubbo - Badgerys Creek is a bad move for regional NSW."

Department of Infrastructure and Regional Development secretary Mike Mrdak told the conference that consultations with Sydney Airport about its first right of refusal over the development of a new airport at Badgerys Creek were proceeding "very well" and would continue in the new year.