State government refuses to rule out toll for new Western Sydney motorway

There could be a new toll for Western Sydney motorists with Roads Minister Melinda Pavey refusing to rule out selling the new motorway to Badgery's Creek Airport to a private operator.

The M12 motorway will run for 16 kilometres from the M7 at Cecil Hills to the Northern Road at Luddenham.

Three interchanges will be built including one to the future airport.

There is $1.25 billion allocated to the project of which 80 percent is funded by the Commonwealth Government.

9NEWS understands there is roughly a $250 million shortfall which has left the Roads Minister Melinda Pavey unable to rule out tolling motorists as a result.

"We will be considering all options going forward to be able to construct this in an envelope that all governments can afford," Minister Pavey said.

"We are not ruling anything in or anything out."

The motorway will be two lanes each way with potential to add an extra lane if there is future demand.

Fifty-five properties will be acquired to make way for the motorway, 15 of which are residential homes.

Rebecca Mammone lives on acreage at Kemps Creek and described the process as distressing.

"It will break the kids heart because they like the farm and they like to live here,” Ms Mammone said.

Opposition Leader Luke Foley argues if the federal government is providing the lion’s share of the funding for the M12, there isn't a need to apply a toll.

"This road which is essentially a duplication of Elizabeth Drive shouldn't be tolled,” Mr Foley said.

An additional one million people are expected to live in Western Sydney within a decade and the new airport will bring 28,000 jobs.

"The Turnbull and Berejiklian governments are delivering the infrastructure needed to make a growing Western Sydney work," Federal Minister for Urban Infrastructure Paul Fletcher said.