The embattled myki ticketing system could be scrapped after the Baillieu government invited transport operators to provide a "warts-and-all" opinion of the smartcard less than one year after it began operating on Melbourne's public transport network.

The expansion of myki to V/Line regional services has also been put on hold and plans to switch off the existing Metcard system by Easter have been abandoned while a major accounting firm provides an independent review of the $1.3 billion system.

Transport Minister Terry Mulder told radio 3AW today that the government would not cancel Metcard until he was confident myki was the right choice for commuters in Melbourne.

"We don't believe we want to go down that pathway until we undestand that we've got a system that functions correctly and doesn't have inherent problems that are going to cause difficulties for the state and for commuters as we go forward," he said.

"We went to the election and we said to the public no one would expect us to pay for something that didn't work because it's taxpayers money, and that's why we're conducting the review that we are.