A shale gas rig in rural Quebec. ((Canadian Press))

Marchers will set off today on a 600-kilometre trek from Rimouski, Que. to Montreal to stir up support for a generation-long moratorium on shale gas development in Quebec.

A spokesman for the event, Philippe Duhamel, said all activity aimed at developing shale gas should be halted for at least 20 years until the extraction process is safer.

He said it's clear the process to unlock natural gas from shale contaminates groundwater and has disastrous consequences on the environment.

The marchers plan to arrive in Montreal on June 18 after stopping in 33 municipalities along the St. Lawrence River where the reserves are found.

The Quebec government halted the industry in March following recommendations in an environmental-assessment report.

The province is now conducting more studies on the ecological risks.