The alignment of the Melbourne Metro rail link could be shifted one block east to Russell Street to avoid the nightmare scenario of shutting down Swanston Street for two or more years.

Fairfax Media understands that influential voices within Public Transport Victoria are arguing that the disruption caused by building the multibillion-dollar rail link between South Kensington and South Yarra could be much reduced if Russell Street was dug up and shut down instead of Swanston Street.

"There are some parties [within PTV] who have expressed the view that the alignment should go up Russell Street," a source who is close to the project said.

Aligning the rail tunnel along Russell Street would require the construction of lengthy pedestrian tunnels so that passengers could interchange at Melbourne Central in the City Loop. But it would have a number of advantages, the source said, including removing the need to shut down the world's busiest tram route and the fact that Russell Street is at a higher elevation than Swanston Street, which would make tunnelling less difficult.