OTTAWA -- It’s a mid-sized pipeline with a bland name, but it packs a helluva punch to Central Canada’s energy supply.

Meet Line 5, a critical connection that will be ordered offline in just two weeks, an unjustified act of treaty-breaking hostility by our American neighbours.

The impact of any shutdown will be widely felt in Ontario and Quebec - at the pump, in the heating bill, in airline ticket prices and even at the backyard barbeque.

And that assumes there aren’t shortages of supply at any price.

Here’s the problem. For 68 years, Enbridge’s Line 5 has been pumping crude and natural gas products like propane across the bottom of the strait linking Lake Huron and Lake Michigan.

Yet despite a flawless safety record, beyond a dent from a tugboat’s dragging anchor, Line 5 carries the “unacceptable risk of a catastrophic oil spill," according to rookie Michigan Gov. Gretchen Whitmer.

And in what seems to be setting up for a second 100 days that’s worse than his first in pipeline politics, U.S. President Joe Biden is not expected to save Line 5 from the governor’s wrath any more than he spared the Keystone XL pipeline from his inauguration day kill order.

If that happens, and there’s an air of inevitability about it, this is going to deliver a blunt-axe whack on Alberta as the oil supplier and to Central Canada as the consumer.

While modest in size at 540,000 barrels a day, Line 5 has an inordinately huge impact on multiple supply chains in Ontario, Quebec and several U.S. states.

It delivers two-thirds of Quebec’s crude requirements and meets 53 per cent of Ontario’s demand. It’s the dominant source of propane supplies in those provinces and several U.S. states. And it imports 100 per cent of the jet fuel for Toronto’s Lester Pearson Airport.

This has left the Canadian government under far greater cross-border duress than the untimely death of Keystone XL because this American irritant will be noticed by consumers in its Ontario base.

To give credit where due, Natural Resources Minister Seamus O’Regan gets high marks from the industry for leading the fight and declaring the continued operation of the pipeline to be “non-negotiable."

That’s brave talk when the guy facing him across the negotiating table could be POTUS.

Even if he wanted to save Line 5, President Biden would face some very awkward optics.

Taking on a friendly governor to rescue a Canadian pipeline which runs underwater at an environmentally-sensitive junction is not exactly in line with his central theme of fighting climate change.

Even the argument that replacing a pipeline with thousands of higher-risk trucks and rail tankers every day only goes so far in pushing Biden outside his comfort zone.

Now, one government insider cautioned me, it’s unlikely the taps will turn off on May 11 at midnight.

There’s mediation under way and court challenges to be fought. The federal government is likely to join Enbridge in the legal action.

And Enbridge has contingency plans for the short term in the event Whitmer suddenly slaps a cork in the pipeline at her border.

Still, it falls on Prime Minister Justin Trudeau to back the Enbridge court actions and use whatever goodwill clout he’s got with American politicians to keep the pipeline operating.

There are literally thousands of jobs on both sides of the border which would be lost to idled refineries if the pipeline is decommissioned. And the proposed tunnel-wrapped, deeply-buried Line 5 replacement is years away from completion, if it’s ever built.

With the ticking clock getting very loud indeed, department officials and our ambassador in Washington are huddling today for yet another strategy meeting.

There’s really nothing new to discuss beyond how much more targeted arm-twisting can be done without antagonizing the new administration.

If all else fails, perhaps we should go back in history to when the U.S. was more concerned about keeping the pipelines flowing than choking off supplies.

A sleepy-sounding Transit Pipeline Treaty was signed in 1977 to prevent public officials from impeding the flow of oil products between the two countries except in emergencies.

Ironically, the prime minister of the day was Pierre Trudeau.

And an influential senator supporting the agreement was …. double irony here … Joe Biden.

Perhaps it’s time Canada resurrected this treaty, one designed specifically to prevent this sort of rogue-state, cross-border energy obstruction, to insist that Line 5’s right to operate is ‘non-negotiable’.

That’s the bottom line.