This follows the announcement of the New South Wales Government planning approval for the West Sydney Airport project back in July.
This final approval applies to the 3.3 km of twin rail tunnel and 2 km of surface track alignment within the airport boundary.
Construction for this phase of the project will also involve the development of two stations and is expected to commence in the coming months.
The project is jointly delivered by The Australian and NSW governments.
Sydney Metro anticipates that tunnel boring machines (TBMs) will be in the ground in 2023, with a tunnelling contract awarded by the end of this year.
The 23 km driverless metro will service western Sydney and the new airport, delivering a vital boost to the economy.
Once completed, it is expected to transport up to 7,740 passengers each hour in each direction, while also taking about 110,000 vehicles off local roads every day, significantly reducing local traffic.
The new railway line will become the transport spine for Greater Western Sydney, connecting communities and travellers with the new Western Sydney International Airport.
The project is expected to support 14,000 jobs, including 250 apprentices.
For more information visit the Sydney Metro website.