Close to a dozen new stations mapped out for Sydney uncovered by opposition

The locations of close to a dozen new stations have been mapped out as the state government considers potential metro and heavy rail extensions around Western Sydney.

In the north-west, the potential stations include Emerton, Bidwell, Marsden Park and Schofields.

In the south-west, they include suburbs like Maryland, Pondicherry and Oran Park.

The map was obtained by the state opposition, as part of a parliamentary order for government documents.

The Minns government has already set aside $40 million for a business case to assess the feasibility of extending the Western Sydney Airport Metro in a northerly direction from St Marys to Tallawong, via Marsden Park and Schofields.

The federal and state governments have also jointly committed $100 million for another business case to assess southerly rail extensions, linking the new airport with Campbelltown and Leppington.

While business cases themselves remain confidential, the map released to the opposition sheds new light on the potential routes each extension could take.

Shadow Transport Minister Natalie Ward said she was "excited" to have uncovered the map.

"We've uncovered the document that's been sitting on [Transport Minister] John Graham's desk for months.

"I think he should be excited too and become clear about what his plan is [and] what Labor will do for Western Sydney."

A mixture of metro and heavy rail

The map shows a northerly extension from St Marys to Tallawong, where the existing metro currently terminates.

It plots out stations at Emerton, Bidwell, Marsden Park and Schofields along the way.

The heavy rail already passes through Schofields, providing an ideal interchange between modes of transport.

The map shows a potential southerly extension would connect Bradfield to Campbelltown, with stops at Bradfield South, Maryland, Pondicherry, Oran Park, Narellan, Mount Annan and Macarthur.

Bradfield South could also be connected to Leppington via a heavy rail link, with a single stop at Rossmore.

Sloane vows to 'build another metro'

Opposition Leader Kellie Sloane said Sydneysiders would get another metro, if they elected a Coalition government.

"I will build another metro and I will plan for future infrastructure in our city," she told 2GB.

While she previously vowed to "progress" a new metro in the city's south-west, Ms Sloane said the opposition was still open to the northern extension between St Marys and Tallawong.

"We've got to make a choice about north and south," she said.

"We need to look at the business case and make a decision."

To pay for it, she previously said the Coalition would seek a new "city deal" from the federal government to fund infrastructure.

While speaking to reporters on Tuesday, Ms Ward was asked whether the Coalition would be prepared to privatise a state asset to pay for a metro, should such a deal not materialise.

"We'll be very clear at the election what our commitments are," she said.

Government managing expectations

Transport Minister John Graham said the government would consider the business cases and make its position clear in "future months".

However, he said the government would not announce any transport plans it could not afford.

"If we put a plan to the public, it will be one we can pay for, and it won't have privatisation," he said.

"I'm very unclear as to whether the opposition in its comments today is for or against privatisation."

He said the government was focused on progressing construction of Sydney Metro West — connecting Westmead with the CBD — as well as the Western Sydney Airport Metro, which would not be ready in time for the first passenger flights in October.

An opening date for the Sydney Metro extension to Bankstown is expected to be announced in the coming weeks.

"We will have room for future transport projects," Mr Graham said.

"But we're not going to do that lightly [and] we're going to not do that quickly. We will step through it in an orderly manner."