Minnesota regulators reaffirmed their support Monday for Enbridge's proposal to replace its aging Line 3 crude oil pipeline across the northern part of the state, while dozens of protesters walked out of the overflow hearing to make a point about climate change.

Minnesota regulators postponed a meeting Tuesday on Enbridge's planned Line 3 replacement after pipeline opponents disrupted the meeting with a bullhorn and a boombox.

Minnesota's Public Utilities Commission has approved Enbridge's proposal for replacing a deteriorating oil pipeline despite strong opposition from some Indigenous people and climate change activists. But a major question -- the line's route -- has yet to be settled, and the fight will likely end up in court.

Passions ran high though people remained polite as Minnesota regulators opened a key hearing Monday that's meant to lead to a final decision on whether to approve Enbridge Energy's proposal for replacing its deteriorating Line 3 crude oil pipeline across northern Minnesota.

Minnesota regulators approved the final environmental review Thursday for Enbridge Energy's proposal to replace its aging Line 3 crude oil pipeline in northern Minnesota, setting the stage for a final decision on the disputed project in June.

Enbridge says the cost of its Line 3 replacement project has risen nine per cent from its original estimate when it was sanctioned in 2014.

The $7.5 billion dollar replacement and expansion project will see up to 760,000 barrels a day from Hardisty, Alta. through Saskatchewan and Manitoba and down to Superior, Wisconsin.