The controversial Keystone XL tar sands pipeline has been dealt a major setback, after a judge revoked a key permit issued by the US army corps of engineers without properly assessing the impact on endangered species.

In a legal challenge brought by a coalition of environmental groups, a federal judge in Montana ordered the army corps to suspend all filling and dredging activities until it conducts formal consultations compliant with the Endangered Species Act.

The ruling revokes the water-crossing permit needed to complete construction of the pipeline, and is expected to cause major delays to the divisive project.

Keystone XL is a 1,179-mile pipeline which would transport around 830,000 barrels of oil a day from the tar sands in Alberta, Canada, to Nebraska, eventually heading to refineries on the Gulf coast.

Campaigners welcomed Wednesday’s ruling as a victory for tribal rights and environmental protection.

“The court has rightfully ruled against the Trump administration’s efforts to fast-track this nasty pipeline at any cost. We won’t allow fossil fuel corporations and backdoor politicians to violate the laws that protect people and the planet,” said Tamara Toles O’Laughlin of the environmental group 350.org