The Minnesota Department of Commerce has asked state utility regulators to vacate their decision to grant Enbridge a permit for a controversial oil pipeline across northern Minnesota.

The Commerce Department, in a regulatory filing Tuesday, claims the Minnesota Public Utilities Commission's (PUC) ruling is "affected by legal error and is unsupported by the evidence."

The Commerce Department officially filed for "reconsideration" of the PUC's decision, which would allow Enbridge to build a new pipeline to replace its aging and decaying Line 3.

It's uncommon for the PUC to reverse its decisions after receiving reconsideration petitions. Often, the petitions serve as a precursor to challenging a PUC decision before the Minnesota Court of Appeals.

Friends of the Headwaters, which opposes the pipeline, also filed a petition for reconsideration with the PUC on Tuesday. Three other environmental groups, the Sierra Club, Honor the Earth and Youth Climate Intervenors, also Tuesday submitted reconsideration petitions to the PUC over the Line 3 ruling. The Mille Lacs Band of Ojibwe also filed a petition.

The PUC decided by a vote of 5-0 in late June to approve the 340-mile pipeline, a $2.6 billion project that had been navigating the regulatory process for more than three years. Enbridge still must get several other state permits, as well as federal permits, but the PUC's decision is particularly crucial.

Enbridge has said the pipeline, which would ferry Canadian oil to the company's terminal in Superior, Wis., is a critical safety enhancement. The current Line 3 is aging and corroding and therefore running at only half capacity. The new Line 3 would restore full capacity.

Environmental groups and some American Indian bands have said the pipeline — which follows a new route — would open a new region of pristine waters to environmental degradation from oil spills.

The Commerce Department has opposed a new Line 3, saying Enbridge has not justified that it's needed. (Enbridge runs six pipelines across Minnesota, including Line 3.)

In its filing Tuesday, the Commerce Department said that state law requires a pipeline applicant to submit a long-range energy demand forecast.

Enbridge didn't do that, the department claims, so the PUC could not fulfill its legal obligation to review such a forecast. Friends of the Headwaters made a similar claim.

Enbridge defended the adequacy of its forecasts. "The petitions filed today are an expected part of this very thorough regulatory process," Enbridge said in a statement.

The Commerce Department also said the PUC erred by granting Enbridge a permit based on "pipeline integrity concerns." Such concerns, the department claims, are the jurisdiction of the federal government, not the PUC.