The Amalgamated Transit Union Local 616 warns a Transit Windsor strike is imminent if a "reasonable, fair offer" doesn't come this weekend.
After months of negotiations, a federal mediator is at the table with the two sides.
The union representing 300 Transit Windsor workers said it would provide an update on Monday, January 29.
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It's the second time the union has warned riders they might have to make alternate travel plans this month. On January 12, it gave Transit Windsor 72-hour advance notice of a strike, only to decide to continue contract negotiations two days later.
"All options for strike action timelines remain open for discussion with members because Transit Windsor has forced our hand," said ATU Canada President John Di Nino.
ATU characterized demands from the employer as "unreasonable" and said the two sides remain at "a considerable impasse."
"We have always kept the best interest of Windsorites in mind, but we are fast approaching the end of the line as frustrations mount," said Local 616 President Dragan Markovic.
At issue are wages, paid sick time off, and working conditions.