Sydney's ongoing Metro program will undergo a major review after it was revealed the cost of the project has already blown out by $21 billion.
After taking over the program from the previous government, Premier Chris Minns said it has been plagued by cost overruns and significant time delays.
"This review is about assembling the right rescue team to come up with solutions to literally get the Metro project back on track," Mr Minns said.
"We're not interested in casting blame - we're interested in finding solutions."
Sydney Metro West has overrun initial estimates by $12 billion to $25.32 billion, a government statement said on Thursday.
The total cost of the City and Southwest sections is $9 billion over its initial estimated cost, with a current price tag of $20.5 billion, according to the statement.
An estimated 2030 opening of the Western Line, at the earliest, constitutes a delay of about five years.
The independent review will examine delivery models, project governance and passenger impacts, and report on the best way to "resuscitate" the state's transport infrastructure pipeline, the government said.
It will be led by eminent transport public servant and former Infrastructure Department head, Mike Mrdak, and the former Department of Transport Deputy director general, Amanda Yeates.
Transport Minister Jo Haylen said her department had inherited significant challenges with the Metro project and across transport more broadly.
"Given the significant investment in the Sydney Metro to date ... an urgent independent review into the whole Sydney metro project is appropriate and warranted," she said.
Business Western Sydney said it didn't support the shelving of any of the Metro lines, saying the transformative projects will change the way Sydneysiders move around.
"We should be given the details of these projects so we can be sure that we get station locations, housing supply and job creation right," executive director David Borger said.
