The NSW government has backed a $1 billion rail upgrade between Sydney and the Central Coast that could pave the way for faster train services.
The state will work with the federal government on the upgrade, with $500 million to be set aside in June 21's state budget, Premier Dominic Perrottet says.
In the run-up to May's federal election, Labor pledged $500 million of Commonwealth funds to a scheme to link Sydney and Newcastle with fast rail services.