Montreal’s proposed light rail system came under fire on Sunday as opponents criticized the project’s environmental impact and financial sustainability.

At a press conference, a broad coalition that included transit experts, environmental groups, citizen groups and trade unions said that proponents of the system have left several important issues unresolved.

The project, formally named the Reseau Electrique Metropolitain (REM), is backed financially by the Caisse de Depot et Placement.

University of British Colombia professor Patrick Condon, who participated via phone, said electric trains are outdates and excessively costly as a means of public transportation.

Advocates compared the prospective train system to the Olympic Statdium in terms of the scale of possible cost overruns.

Construction of the 67 kilometre tracks is expected to begin this summer with service to begin in 2020.

The group asked for a parliamentary committee be formed with a mandate to evaluate the project and determine whether is represents a gain for transit users, the environment and taxpayers.

In a letter dated Jan. 27, Projet Montreal leader Valerie Plante said the project, in its current form, “doesn’t satisfactorily address” residents’ transit issues.

Plante said the train line would not relieve congestion on the metro’s Orange Line and would not help residents in the eastern portion of the city reach downtown.

“Any massive investment in Montreal public transit should improve the mobility of residents in remote and underserved areas, both in the East End and West Island,” she said. “In its present state, the REM does not respond satisfactorily to this objective.”

A recent report filed by the Office of Public Hearings on the Environment gave low marks to the project, expressing reservations about its environmental footprint and profitability.

Despite the criticism, Premier Philippe Couillard and Mayor Denis Coderre have both said the project would go ahead, with Couillard suggesting the Office of Public Hearings’ report had overstepped the department’s mandate.