The deep divisions over PolyMet Mining Corp.'s proposed $1 billion copper-nickel mine project were on full display at the State Capitol on Tuesday, as both supporters and opponents rallied there following the company's petition to the Minnesota Supreme Court.

As expected, PolyMet asked the state Supreme Court to reverse a recent appellate decision that blocked three permits it needs to begin mine construction. The permits were issued by the state Department of Natural Resources (DNR), and the decision sent the permits back to the agency for a contested case hearing.

In a statement, PolyMet President Jon Cherry said the Court of Appeals decision in January "effectively opened the door to an unpredictable loop of review and additional litigation for Minnesota permittees."

"The court's ruling increases uncertainty and permitting time not only for mining projects but also for many other projects in the state that require DNR or MPCA [Minnesota Pollution Control Agency] permits," Cherry said.

PolyMet argued in its petition that state regulators shouldn't be required to hold a contested case hearing on a project if they don't think it will help them make a decision.

Meanwhile, a diverse group of religious leaders with Minnesota Interfaith Power & Light delivered an open letter to Gov. Tim Walz, state environmental regulators and lawmakers asking them to accept the judgment of the Appeals Court. The group does not want the DNR to also petition the state Supreme Court for a review.

The group said it had a moral responsibility to speak out against PolyMet because of safety risks, pollution from toxic metals and sulfide generated by the mine, and the fact it would violate the treaty with the Fond du Lac Band of Lake Superior Chippewa. The letter had 246 signatures, mostly from spiritual leaders. About a dozen people with the group held a prayer circle, sang and performed a Native drum song.

The DNR has until the end of Wednesday to petition the Supreme Court for a review. As of Tuesday, the agency had not indicated what it plans to do.

In the State Office Building on Tuesday, the pro-mining group Jobs for Minnesotans led a press briefing to show solidarity with the company they hope will revitalize the mining industry on the Iron Range.

The event included the Minnesota Building and Construction Trades Council, the state Chamber of Commerce, United Steelworkers and others. That coalition called for a less burdensome regulatory process to encourage job growth. It took more than a decade for PolyMet to secure the permits for the open-pit mine it wants to build near Babbitt and Hoyt Lakes in northeast Minnesota.

PolyMet is owned by Glencore, a mining and commodity trading conglomerate based in Switzerland. Glencore is being investigated by the U.S. Department of Justice under foreign corruption and money-laundering statutes.

A fourth PolyMet permit, a water pollution permit issued by the MPCA, remains suspended pending a decision by a Ramsey County District Court judge about whether state pollution regulators engaged in "procedural irregularities" as they processed the permit. That permit and the process is the subject of two investigations, one by the Office of the Legislature Auditor and one by the U.S. Environmental Protection Agency's Inspector General.