The controversial sky rail project in south-east Melbourne is heading to the Supreme Court.

Residents living along the Cranbourne-Packenham train line have launched a last ditch bid to derail the project, filing documents in the Supreme Court on Wednesday claiming the government's decision to allow elevated rail was "unreasonable". Hearings are expected to begin on Tuesday.

The Andrews government has promised to remove 50 level crossings across Melbourne as part of the $1.6 billion project. Once the project is complete there will be no level crossings between Caulfield and Dandenong on the Cranbourne-Pakenham line.

The Lower Our Tracks Inc protest group says the nine level crossings set to be removed from the Cranbourne-Packenham line should be re-built under the road - as they have been in nearby Bentleigh, Ormond and McKinnon - not above.