SEATTLE - In a dramatic turnaround, a federal judge has ruled that permits to complete the Dakota Access pipeline must be reconsidered, and the Standing Rock Sioux Tribe has demanded the flow of oil through the pipeline be stopped.

Completion of the controversial pipeline was stopped by the Obama administration last December, with a call for an environmental-impact statement to assess risks.

However, the judge wrote in his ruling, "As we all know, elections have consequences, and the government's position on the easement shifted significantly once President Trump assumed office on January 20, 2017."

President Donald Trump called on the U.S. Army Corps of Engineers to issue the permits, which it did shortly after he took office. Completion of the pipeline swiftly followed, as contractors drilled under a lake formed by a dam on the Missouri River, to hook up the two ends of the pipeline. The flow of oil began June 1.

But on Wednesday, U.S. District Court Judge James Boasberg for the District of Columbia said in a 91-page decision that the Corps did not adequately consider the impacts of an oil spill on the tribe's fishing rights, hunting rights, or issues of environmental justice when it issued the permits needed to complete the project. The Corps must now reconsider those aspects under the judge's demand that the agency substantiate its decision to issue the permits.

"This is a significant victory," said Jan Hasselman, attorney for Earthjustice in Seattle, representing the tribe. He said the tribe in a status conference before the judge next week will also demand that the flow of oil be stopped while the remand is underway.

Standing Rock Sioux Tribal Chairman Dave Archambault II said in a statement: "We applaud the courts for protecting our laws and regulations from undue political influence and will ask the court to shut down pipeline operations immediately."

The developer, Energy Transfer Partners, could not immediately be reached for comment.

Hasselman said the court found three separate violations of legal standards when the Corps issued the permits to complete the pipeline.

An analysis of the potential for spills by an outside analyst was not adequately addressed. The Corps also didn't consider risks to hunting and fishing rights reserved by the tribe in waters of Lake Oahe, formed by the damming of the Missouri River, where the pipeline crossing was drilled.

Finally, the environmental-justice concerns raised by the tribe were also not adequately addressed, nor the highly controversial nature of the project.

While the tribe lost on other points it raised, "These are not minor, paperwork transgressions," Hasselman said, who called the ruling a "major victory for the tribe."

If the judge won't shut down the flow of oil as the Corps does its reconsideration, the tribe will demand a deadline for its work, Hasselman said. "If pipeline operations are suspended, they can take all the time they want," he added.

The decision will turn on how disruptive turnoff would be, and the likelihood that the deficiencies in the Corps' review can be remedied, Boasberg wrote in his ruling.

The $3.8 billion pipeline runs for 1,168 miles across North and South Dakota, Iowa, and Illinois to carry more than half a million gallons a day of Bakken crude to hook up to other pipelines in Patoka, Ill.

The tribe argued the pipeline, routed within a half mile of its reservation, puts its water supply in the Missouri River and tribal lands, including sacred sites, unduly at risk.

Its fight against the pipeline was joined by tribes from around the Northwest and the nation, as well as opponents from all walks of life from around the globe.

Energy Transfer Partners has argued the pipeline is safe and preferable to either tanker trucks or oil trains for the transport of an essential commodity.