The State Opposition has accused the Government of walking away from a promise to provide light rail to Sydney Olympic Park during the first stage of construction, with concerns the employment hub will be dropped from the plan altogether.

In late 2015, the Government unveiled a 22-kilometre preferred route for the Parramatta Light Rail project, stretching from Strathfield to Westmead, via Olympic Park.

But today that changed when it announced it would build the project in two stages, starting with a 12-kilometre line from Westmead to Parramatta and Carlingford.

That means the growing residential and business hub at Olympic Park will not be serviced by light rail until the second stage of the project, which Opposition Leader Luke Foley believes will never be built.

"I'm angry," Mr Foley said.

"What's really happened today is the Liberals have walked away from light rail to and from Olympic Park."

We're 'absolutely' committed to stage two, Premier insists

Mr Foley said Olympic Park was home to a vital employment hub and the fastest growing high-rise residential development in Sydney, and said the Government was failing to deliver the transport it had promised.

Sydney Olympic Park not included on the Government's list of preferred locations. ( Supplied: NSW Government )

But the Premier Gladys Berejiklian insisted the Government was "absolutely" committed to stage two of the project.

Transport Minister Andrew Constance said because the light rail would intersect with the Metro line planned for the area, stage two needed to be carefully thought out.

"We're building a first stage which is the same length as the CBD light rail, 12 kilometres 16 accessible stops and we're going to do our homework in relation to stage two this year," Mr Constance said.

He said more details would be announced by the end of the year.

The new plans for the first stage of the project named 16 potential stops, including Westmead Hospital, Parramatta, Dundas, Camellia and Telopea.

Stage one will be complete by 2023, but Mr Constance was unable to put a start or finish date on the second stage of the project.

Mr Constance confirmed a handful of homes and a 28-unit apartment block would have to be acquired for the project and door-knocking of affected residents had already begun.

The Western Sydney Director of the NSW Business Chamber David Borger said stage one would be a game-changer for western Sydney.

But he urged the Government to move swiftly on to Stage Two.