GREAT FALLS – The developer of the Keystone XL pipeline can’t start digging, building man camps or any other pre-construction field work until a full environmental review is completed, a federal judge in Montana ruled Friday.

U.S. District Judge Brian Morris’ ruling was a clarification of a Nov. 8 decision, where he halted construction by TransCanada Corp but allowed certain pre-construction activities.

Friday’s decision further curtailed those pre-construction activities to include planning and other activities related to developing a full environmental review. All physical construction is blocked.

In his ruling, Morris stated that pre-construction activity could create “bureaucratic momentum” that would discourage other federal agencies from rejecting the project.

The ruling was a win for the environmental groups, who had sued to block the pipeline.

“Implicit in the original injunction by Judge Morris is the notion that TransCanada’s KXL pipeline has not proven to be safe or beneficial to the United States. We find it hard to imagine a scenario whereby piping these dangerous tar sands, which simply uses the U.S. as a pass-through to the global market, accomplishes that goal,” said Dena Hoff, a Glendive-area farmer and member of Northern Plains Resource Council, one of the plaintiffs in the suit.

Other plaintiffs include Indigenous Environmental Network and the North Coast River Alliance.

TransCanada is seeking to build a 1,179-mile line from the tar sands of Alberta, crossing a half dozen states including Montana, and connecting with an existing line in Nebraska to head to the Gulf Coast.

In the last few months, pipelines and other equipment have been hauled to Montana in anticipation of starting construction.