The union has said negotiations between the two sides began in April and members have been working without a contract since June 1.
Local president Rob Cormier has said the union’s key issues include job security and job safety relating to hiring contract workers from outside companies.
“Our members have made it utterly clear. We will not accept a deal unless it addresses our primary concern, which is contracting out,” Cormier said in a written statement.
“We have had enough—starting Monday, we will walk the picket lines until we reach an agreement that protects job security for our current and future members,” he said in the statement.
Cormier said the union remains committed to meeting with Metrolinx to reach a deal that addresses members’ concerns.
Anne Marie Aikins, head of media and public relations at Metrolinx, said if the strikes goes ahead, there will be no bus service starting Monday, though trains will continue to operate as scheduled.
“We will be working throughout the weekend to get an agreement and remain open to discussing ways forward with our ATU employees,” Aikins said in an emailed statement.
The planned strike is expected to come three days after thousands of Ontario education workers represented by the Canadian Union of Public Employees walked off the job indefinitely. ATU has said it supports those workers.