Members of Canada's Unifor union staged a sit-down protest at GM's Oshawa Assembly Plant near Toronto. The move follows GM's decision to decline any potential plans proposed by Unifor at a meeting held Tuesday in Detroit.

Wednesday's sit-down follows a similar protest held on Tuesday during the meeting, which ended in a walk-out about an hour before the shift was scheduled to end.

Unifor posted videos to Twitter from inside Oshawa Assembly that showed buzzers going off, which it writes were going off because the line was down.

The buzzers are sounding in the Oshawa Assembly Plant tonight because the line is down. Workers are protesting @GM and it's betrayal of Canadian workers and consumers after it rejected Unifor's proposed solutions to #SaveOshawaGM today. #canlab

- Unifor Canada (@UniforTheUnion) January 9, 2019
"We understand our union's frustration but need to now work together to deliver support, transition and training for our employees for new opportunities over the coming year," GM Canada spokeswoman Jennifer Wright told Automotive News, echoing the manufacturer's comments yesterday, following discussions.

Unifor, meanwhile, released the findings of an independent study it commissioned claiming that the economic impact of shutting the plant down would lead to tens of thousands of lost jobs in the area and $1 billion per year in government revenue.

GM announced late last year that it would not be allocating new products to the Oshawa, Lordstown, or Detroit-Hamtramck Assembly plants.

The impact of the protests on production at Oshawa Assembly-which builds the Chevrolet Impala, the Cadillac XTS, and finishes last-generation 1500s-is unclear.

Unifor President Jerry Dias told Automotive News he did not know how long protests would continue.

"We're just playing it by ear," said Dias. "Our members are going to make up their own mind, and we're going to support whatever actions they want to take. It's not more complicated than that."

The union is planning a mass rally in Windsor on Friday, though.