Unifor local 594 members are voting in favour of the special mediators; recommendations that were given to both sides of the labour dispute last week.
Members voted 98% in favour of the recommendations, which would have seen changes to the employee pension plan.
While Unifor says they accept the recommendations, Federated Co-op says they are unable to accept the report in its entirety, saying recent developments in the energy industry, including the COVID-19 pandemic, have put FCL in a worse situation than when talks began.
Unifor then accused FCL of using the COVID-19 pandemic to gain leverage in talks.
The over-700 union members have been locked out of the refinery since early December.