A Superior Court judge in Thunder Bay is reserving his ruling in the first battle of what is expected to be a long courtroom war between Resolute Forest Products and Greenpeace Canada.

The forestry giant is suing the environmental group for $5 million for "defamation, malicious falsehood and intentional interference with economic relations."

The claim relates to a Greenpeace campaign, beginning in 2012, that was critical of Resolute's forest practices.

Greenpeace forest campaigner Shane Moffatt is named as part of the suit, which he calls a 'SLAPP' — an acronym for strategic lawsuits against public participation.

"It's our opinion that this suit is intended to send the message not to criticize Resolute," Moffatt said outside the Thunder Bay courthouse on Thursday. "In our opinion, if Resolute had their way no one would be criticizing them at all."

'Surreptitious conduct'

Greenpeace asked the court on Thursday to strike down Resolute's claim of intentional interference.

Lawyer Jordan Goldblatt argued that Resolute had not shown the court that the company suffered financial losses related to the environmental group's interactions with its customers.

But the lawyer for Resolute said the company is unable to make those connections until it has full disclosure from Greenpeace about its tactics.

"We can't be expected to plead full particulars," Resolute's lawyer Arthur Hamilton told the court. "In our circumstances you have Greenpeace deliberately keeping Resolute out of the loop."

Hamilton said the Greenpeace campaign was "rich in surreptitious conduct" and that Greenpeace contacted Resolute's customers to "get them to leave Resolute at any cost for any reason."

If the case proceeds, Hamilton said Resolute will be seeking internal documents and emails from Greenpeace to reveal its campaign strategy.

Meanwhile Moffatt said Greenpeace will "vigorously defend" itself against the lawsuit, which he calls an attempt to intimidate himself and other environmentalists.

There's no date set for the ruling on Thursday's motion.  Once that's settled, the broader defamation case will still need to be addressed through the courts.