REGINA -- Hundreds of union workers at the Regina Co-op Refinery went on strike on Thursday at shortly after 4:30 p.m. 

The workers served a strike notice on Tuesday, followed by a lockout notice from the refinery. 

Kevin Bittman, the president of Unifor Local 594, said the company was not willing to budge.

“We’ve been pretty clear from the start. Three years ago we gave major concessions on pension. This year they came back on major rollbacks and we’re not willing to go back after $2.5 billion since the last time we conceded to them,” Bittman said.

In a press release, Co-op Refinery said it is willing to continue talks. It confirmed that all Unifor workers have been locked out of the refinery as of 5:30 p.m. on Thursday. The release said the move ensures the refinery remains operational in order to protect the western Canada fuel supply. 

“It is disappointing that the Unifor 594 Executive would not return to the bargaining table,” Gil Le Dressay, Vice-President of Refinery Operations, said. 

“Despite our best efforts to resume negotiations yesterday, the Unifor 594 executive has decided to put their membership on the picket line. As we told them, the only way we can ensure a safe operating environment is to lock the union out and have our management team assume the safe operation of the refinery,” Le Dressay said. 

“We simply can’t run the risk of employees conducting rotating strikes and walking off the job in our safety-sensitive operating environment.”

The press release said Co-op has offered an 11.75 per cent wage increase over four years, and has offered unionized employees the option to remain on their current pension plan or move to the company’s lucrative Defined Contribution (DC) Pension Plan that management and all new hires are on.

The provincial government has provided a mediator, and continues to communicate with both sides.

"By way of mediation, arbitration or conciliation we'll make all the facilities that we have available at any time,” Don Morgan, Minister of Labour Relations and Workplace Safety, said. “We're going to continue to maintain the lines of communication as well as we can."