About 900 unionized staff with Edmonton Catholic Schools say they will set up picket lines at 8 a.m. Monday if a new contract is not reached over the weekend.
The workers include secretaries, teacher assistants and office support staff, who voted Wednesday to reject the district's latest contract offer.
Lori Nagy, spokeswoman for the Catholic board, says schools will remain open if a strike occurs, and that a contingency plan is in place to deal with a potential labour disruption.
But the Communication Energy and Paperworkers Union of Canada, which represents the affected employees, says it will still be difficult for the schools to function.
Edmonton Catholic has 87 schools with more than 34,000 students. (CHED)