Liberal Senator Paul Massicotte owns the forest land and wants to develop it, but his plans have met strong opposition.
Marilou Alarie, the head of a group trying to save the woodland, said developing the Hirondelles forest would damage several types of endangered plants.
"It's a mystery, really, because the population is against it, the scientific community is against it. We have signed the most important petition in the history of the city," said Alarie of Citizens for the Protection of the Forêt des Hirondelles.
"It didn't make sense to me, in 2012, that we would do such a thing."
Her group has been fighting for six years to safeguard the land, ever since it was sold by the Saint Bruno golf course. Locals often use the property for its walking trails.
Massicotte wants to build 30 homes on the woodland. Opponents to the idea are asking for an injunction against any construction until they've had a chance to seek environmental protection for the forest.
Alarie said despite the public's opposition, the project is supported by the mayor of Saint Bruno, Claude Benjamin.