The trial date for the case of the cities of Moreland and Yarra against the East West Link will be heard in the Supreme Court on December 15 following a directions hearing on Friday.

The councils want a judicial review of Planning Minister Matthew Guy's decision in June to approve the government's flagship major project, on the grounds the planning process was botched.

Mr Guy made important changes to the reference design for the 5.2-kilometre freeway, most notably when he deleted a planned interchange at Elliott Avenue in Royal Park in favour of an alternative freeway exit onto Flemington Road. This freeway exit was not part of the planning process.

Two consortiums are bidding to build the $8 billion road between the Eastern Freeway and CityLink and the government is seeking to sign contracts before it enters caretaker mode on November 4. Labor opposes the road but says it would honour contracts for the project, should it win November's poll.

Andrew Herington, a former Brumby government adviser who is playing a leading role in community campaigns against the road, said the legal challenge could still derail the project despite being deferred until well after contracts are due to be signed.

"If the planning approval is overturned in December, they will have to go back to the drawing board, which would add six to 12 months to any construction schedule," Mr Herington said.

"Companies would be commencing work without certainty that the approvals will stand."

The Mayor of Yarra,  Jackie Fristacky, said: "This legal action is about the right of local communities to challenge governments when they don't follow the rules around major projects. It is important to be clear, contract or no contract, the project cannot be built unless there is a valid approval."

The Napthine government declined to comment on the legal challenge.

"We are committed to delivering this critical project on schedule. It would not be appropriate to comment on the judicial review process or matters before the court," a spokeswoman said.

Mayor of Moreland Lambros Tapinos said Premier Denis Napthine should secure a mandate from the Victorian public for the project.

The councils' challenge is one of three being heard against the road project. Labor's shadow roads minister Luke Donnellan is seeking to force the government to release the project business case in the Victorian Civil and Administrative Tribunal, and Brunswick resident Anthony Murphy has mounted a Supreme Court challenge on the argument the government has breached consumer protection laws, by making "misleading representations" about its estimated cost benefits.