U.S. Rep. Ilhan Omar stood with three congressional colleagues along the shore of the Mississippi River on Friday and asked President Joe Biden to stop construction on the nearly complete Enbridge pipeline built to transfer oil from Canada to Superior, Wis.

"We have been encouraged by Joe Biden's boldness so far," Omar said, referencing his January decision to cancel a border-crossing permit for the Keystone XL pipeline that would have carried oil from Canada to Nebraska. "Now we have another chance to reject a moving pipeline. We hope you will act."

Her message to Biden marked an intensified political push for federal intervention in the $3 billion project, the subject of a letter to the president signed by 63 elected officials Monday. In that letter, and again during a news conference Friday at Minneapolis' Boom Island Park, Omar and other Democrats said the Enbridge project has raised concerns about violations of Indigenous land treaties, violence against Indigenous women and environmental impacts.

Members of Gov. Tim Walz's administration, which handled a large portion of the project's permitting, on Wednesday sent a point-by-point response to members of Congress and the Legislature calling some of those claims "false or misleading."

Minnesota Republican legislators condemned the visit from the four members of Congress — all women of color who are part of the progressive "Squad" in Washington — saying the trip "will only serve to incite the obstructionists."

Along with U.S. Reps. Cori Bush, D-Mo.; Ayanna Pressley, D-Mass.; Rashida Tlaib, D-Mich.; and state Sen. Mary Kunesh, Omar will visit Bemidji and other parts of northern Minnesota this weekend to speak with members of Indigenous communities and others who have been protesting construction of the pipeline, which crosses the Mississippi River twice near its headwaters.

"The water that flows from this point will carry whatever dirty fossil fuels it picks up right on down to my district," said Bush, who represents the St. Louis area.

Tlaib lambasted Enbridge for a massive 2010 oil spill in her home state, as well as for defying Michigan Gov. Gretchen Whitmer's orders to shut down the company's Line 5 pipeline out of concern for environmental effects on the Great Lakes.

After a six-year battle through Minnesota's regulatory process, work on the 340-mile Line 3 is more than 90% complete. Enbridge has said it will begin pumping oil during the fourth quarter.

The pipeline replaces the 1960s-vintage original Line 3, which is corroding and can run at only 51% capacity. Enbridge has repeatedly said the new pipeline is a significant safety improvement; it will restore the full flow and boost the company's earnings.

New Line 3 runs partly on a new route. Pipeline opponents say it will expose new regions of Minnesota's lakes, rivers and wild rice waters to oil-spill degradation — and will exacerbate climate change.

Protests along the pipeline route have heated up this summer while key legal challenges by pipeline opponents have so far failed.

The Minnesota Supreme Court recently rejected a petition from environmental groups and tribes asking judges to overturn the Minnesota Public Utilities Commission's 2020 final approval of the pipeline. Then on Monday, the Minnesota Court of Appeals ruled against pipeline opponents challenging the project's state water quality and wetland permit.

A suit against the U.S. Army Corps of Engineers, which granted a water and wetlands permit for Line 3, rolls on in a federal court in Washington, D.C.

Pipeline opponents calling on Biden to quash Line 3 had hoped that his administration would effectively do so through the federal suit. But in a key court filing in late June, the Army Corps of Engineers strongly defended its Line 3 permit.

Omar said Friday that she and others are asking the president to revoke that permit. But Biden likely is facing competing political pressure from split factions within his party — environmental advocates vs. organized labor.

Line 3, one of the largest construction projects in Minnesota in recent years, is a union project. At a State Capitol news conference earlier Friday, GOP U.S. Rep. Pete Stauber and others, including a union leader and White Earth band member, preemptively spoke in favor of the pipeline.

Stauber and others called it "hypocrisy" by Omar and others to use jet fuel to fly to Minnesota for a news conference. The congressman said the fuel for their flights may have come from the Rosemount refinery fed by Line 3.

He also questioned what he called the "Socialist Democrats" opposing union jobs. He decried how "Hollywood elites" had previously come to northern Minnesota to "protest our way of life," and he pledged to protect "good-paying jobs" and skilled union labor.

In response, Omar said Stauber was advocating for Calgary-based Enbridge instead of his constituents and questioned why he hasn't supported workers pushing for a federal minimum wage increase and protections for unions organizing.

Earlier this week, a letter from the United Nations Committee on the Elimination of Racial Discrimination emboldened pipeline opponents by asking the U.S. State Department to launch an inquiry into claims that Line 3 is infringing on Indigenous rights by harming wild rice and encroaching on land and sacred sites.

Another spark of hope for opponents emerged Friday when a federal judge rejected the Minnesota Department of Natural Resource's move to quash a novel suit challenging Enbridge's increased water use, which was 10 times greater than originally planned for the project. The lawsuit — which names manoomin, the Ojibwe word for wild rice, as the lead plaintiff — will proceed in tribal court.

Staff writers Rochelle Olson and Mike Hughlett contributed to this report.

Katie Galioto • 612-673-4478

Correction: Previous versions of this story misattributed a statement about a 2010 Michigan oil spill.