Gas prices may spike in Ontario and Quebec — because of an obscure court case in Michigan

A Michigan regulatory battle will almost certainly hit Canadian drivers at the pumps. Line 5 has faced ongoing legal challenges and shutdown attempts since 2019, adding uncertainty to a critical supply chain with limited immediate substitutes.

Here’s a look at what the ruling entails, how it affects energy costs in Eastern Canada and how consumers can prepare financially as legal proceedings continue.

What the Michigan Supreme Court ruled

The court did not issue a shutdown order for Line 5. Instead, it vacated a 2023 permit granted by the Michigan Public Service Commission (MPSC) — the state’s energy regulator — for Enbridge’s proposed four-mile tunnel segment beneath the Straits of Mackinac. The high court ruled that the commission failed to properly evaluate the project’s broader environmental impact under state environmental law.

As a result, the MPSC must conduct a new review. The replacement tunnel also requires remaining state and federal authorizations before construction can proceed. In the interim, the existing dual pipeline crossing the lakebed continues to operate and transport product to Sarnia, Ontario.

Why a US court decision impacts Canadian consumers

Line 5 transports approximately 540,000 barrels per day of crude oil and natural gas liquids from Superior, Wisconsin, to Sarnia, Ontario. This supply feeds refineries supplying close to half of Ontario and Quebec’s transportation fuel and heating oil needs.

Beyond the tunnel permitting case, separate litigation remains active. Michigan’s attorney general continues to pursue a lawsuit seeking a full operational shutdown of the existing line. Earlier in 2026, the US Supreme Court remanded that case back to state courts, keeping the broader question of the pipeline’s long-term operating status active within the legal system.

Historical precedent for supply constraints

Physical interruptions demonstrate how sensitive the regional market is to supply shifts. In 2020, a temporary operational pause on Line 5 following a vessel anchor strike prompted market analysts to warn of potential fuel price spikes across Ontario and Quebec due to limited short-term transport alternatives.

While that event involved an operational pause rather than a court ruling, it illustrated a structural reality: Regional refineries depend heavily on a single primary corridor with minimal immediate redundancy.

Regional responses and alternative proposals

In response to ongoing legal friction in Michigan, political leaders — including Ontario Premier Doug Ford — have reiterated calls for alternative infrastructure, such as proposed domestic pipeline corridors connecting Western Canadian crude directly to Eastern refineries without crossing international borders.

However, any proposed major pipeline project remains years away from potential regulatory approval and construction. For the near term, Eastern Canada’s fuel supply chain remains tied to Line 5 and its ongoing court proceedings.

Practical financial planning steps for households

Regulatory reviews move slowly, meaning immediate panic-buying or drastic budget overhauls are unnecessary. However, incorporating basic financial buffers helps manage potential energy price volatility:

• Monitor regional fuel trends: Track local pump prices before planning major road trips or large fuel purchases, utilizing resources like Natural Resources Canada’s daily fuel price reporting.
• Review heating arrangements: If you rely on home heating oil or propane in Ontario or Quebec, contact your fuel provider to evaluate fixed-rate or capped pricing contracts prior to winter demand surges.
• Incorporate a modest fuel buffer: Allocate a small contingency buffer — such as $20 to $30 monthly — within your household budget to absorb potential short-term fuel or utility fluctuations.
• Follow regulatory milestones: Track updates from the Michigan Public Service Commission’s renewed review and state court proceedings to stay informed on potential long-term supply shifts.

While the pipeline continues to operate normally today, the court’s ruling serves as a reminder of the complex supply chain supporting regional energy needs. Taking proactive steps to build flexibility into your household budget ensures you remain prepared regardless of how legal proceedings unfold.