A federal judge will hear arguments Tuesday about whether to stop the final bit of construction on the disputed Dakota Access pipeline, perhaps just days before it could start moving oil.

U.S. District Judge James Boasberg in Washington, D.C., will consider a request by the Standing Rock and Cheyenne River Sioux tribes to order the Army Corps of Engineers to withdraw permission for developer Energy Transfer Partners to lay pipe under Lake Oahe in North Dakota. The stretch under the Missouri River reservoir is the last piece of construction for the $3.8 billion pipeline that's to move oil through the Dakotas and Iowa to a shipping point in Illinois.

The tribes argue that the mere existence of an oil pipeline under the reservoir that provides water to the neighboring reservations violates their right to practice their religion, which relies on clean water.

"The granting of the easement and resulting construction activity violates the tribe's and its members' constitutional rights, and will result in immediate and irreparable harm to the tribe and its members before this court will be able to rule on the merits of this claim," tribal attorney Nicole Ducheneaux said in court documents.

When they filed the lawsuit last summer, the tribes argued that the pipeline threatens Native American cultural sites and their water supply. Their religion argument is new, however, and both the Corps and Energy Transfer Partners argue that the delay in raising it is a reason for Boasberg to reject the argument.

Company attorney William Scherman also said the tribes' claim is suspect based on other man-made infrastructure under the lake, and that the company respects the tribe's religious beliefs but has no legal duty to make concessions for them.

Corps attorney Erica Zilioli said the government's permission for the company to lay pipe under the lake "does not substantially burden the exercise of the tribe's religious beliefs."

Pipes for the proposed Dakota Access pipeline are stacked at a staging area in Worthing, S.D., May 9, 2015. Nati Harnik | AP 2015

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Earlier this month, Boasberg declined the tribes' request to order an immediate halt to the pipeline construction, ruling that as long as oil wasn't flowing through the pipeline, there was no imminent harm to the tribes.

In a court filing Friday, Ducheneaux argued the claim is "about the religious harm arising from the mere siting of this pipeline under the tribe's sacred waters."

Boasberg's decision on the matter won't be the end of the court battle. Both tribes have asked him to overturn the federal permission for the Lake Oahe crossing and to bar the Corps from granting permission in the future. The judge won't rule until at least April.

Hundreds and sometimes thousands of pipeline opponents who sided with tribal opposition to the pipeline camped on federal land near the drill site for months, often clashing with police. There have been about 750 arrests in the region since August. Authorities last week closed the camp in advance of spring flooding season and set up roadblocks to prevent protesters from returning.

Work under Lake Oahe had been held up in the courts until President Donald Trump last month instructed the Corps to advance construction. The Army is involved because its engineering branch manages the river and its system of hydroelectric dams, which is owned by the federal government.

Texas-based Energy Transfer Partners began drilling under the lake Feb. 8. The pipeline could be operating as early as Monday and no later than early April, according to Scherman.