Sixteen Greenpeace activists will plead not guilty to charges arising from a protest at the Shell upgrader expansion site in Fort Saskatchewan on Oct. 4, a provincial court in Sherwood Park, Alta., heard Wednesday.

An unidentified protester holds a banner during a protest at Shell's upgrader expansion in Fort Saskatchewan, Alta., on Oct.4. (Greenpeace)The protestors from Canada, France, Brazil and Australia were charged with mischief and breaking and entering after chaining themselves to smokestacks during the incident.

"My clients don't believe that you should criminalize free speech, which is what we think is happening here," said lawyer Brian Beresh, who represents the group. "And as a result, there will be trials."

During the 24-hour demonstration, the protestors unfurled banners reading "Climate Crime" and "Climate SOS" to draw attention to an industry they believe is a significant contributor to climate change.

"They believe that they were justified in the actions in terms of bringing this to the public attention," Beresh said.

'No criminal law broken'

"We've had civil disobedience ever since mankind has existed," Beresh said. "We say there's been no criminal law broken, and we're prepared to face this in court."

The demonstration followed two other recent protests connected to oilsands development in Alberta.

On Sept. 16, Greenpeace activists chained themselves to two massive oilsands trucks in Shell's Albian Sands mine, north of Fort McMurray. On Sept. 30, about 20 protesters were arrested after blocking work at Suncor Energy's open-pit mine in northern Alberta.

The accused were not required to be in court Wednesday. The case will be back before the judge next month.