By James McCarten in Washington

The U.S. judge presiding over Michigan’s bid to shut down the Line 5 pipeline has given her blessing to the state to appeal one of her key findings, breathing new life into a strategy that hinges on getting the dispute heard by a lower court.

Back in August, District Court Judge Janet Neff rejected a motion from Michigan Attorney General Dana Nessel to send the case back to state court, where Nessel has acknowledged they have a better chance of winning.

But earlier this week, Neff granted Nessel’s request to certify that August decision, clearing the way for what’s known as an interlocutory appeal — formally asking an appeals court to reverse a judge’s order before a final decision in the case has been made.

Such certifications, rare in U.S. law, must meet certain conditions, Neff wrote in a decision Tuesday: that they involve a “controlling question of law” that’s likely to generate a difference of opinion, and that an appeal could expedite a resolution.

“Having reviewed the record, the court concludes that this dispute is one of the exceptional situations that compels certification,” the order reads.

“Each of the three issues identified by (the) plaintiff involve a controlling question of law, there is substantial ground for difference of opinion, and an immediate appeal will materially advance the ultimate termination of the litigation.”

Neff has also ordered that the current case — just one of several open files involving Enbridge Inc., Line 5 and the state of Michigan — remain stayed and administratively closed until the appeal is resolved.

Michigan has been in court for years with Calgary-based Enbridge in an effort to shut down Line 5, fearing a disaster in the Straits of Mackinac, the ecologically sensitive region where the pipeline crosses the Great Lakes.

Enbridge and its allies, which include the federal Liberal government in Ottawa, insist the pipeline is safe, that planned upgrades will make it even safer, and that a shutdown would impart too great a cost for the North American economy to bear.

The legal saga, however, has been dominated almost from the start by arcane procedural questions about jurisdiction and precedent, with Tuesday’s decision likely to deepen that morass even more.

Nessel has made three central arguments: that Enbridge flouted a 30-day window to move the case to district court; that Neff relied too heavily on her own earlier decision to reject Nessel’s motion in a separate but nearly identical Line 5 case; and that the question of jurisdiction has not been properly settled.

“The attorney general believes that the federal trial court clearly erred when it refused to send the case back to state court,” Nessel’s office said in a statement. “The order allows (Nessel) to ask the federal court of appeals to step in and right this wrong.”

Environmental groups in Michigan that back the state’s efforts against Line 5 also cheered the decision.

“This ruling is good news for the Great Lakes. Enbridge’s use of the federal courts to delay the state’s ability to protect the Great Lakes is unconscionable,” National Wildlife Federation counsel Andy Buchsbaum said in a statement.

“We hope that this will get the case back on track quickly so the Great Lakes doesn’t suffer from a massive oil spill.”

Enbridge, for its part, sees things differently.

A statement from the company cited Neff’s own words from the August 2022 decision in which she accused Nessel of seeking “a race to judgment and a collision course between the state and federal forum.”

“The attorney general seeks to undermine these considerations and promote gamesmanship and forum shopping,” Enbridge said, “while ignoring the substantial federal issues that are properly decided in federal court and not state court.”

This report by The Canadian Press was first published Feb. 23, 2023.