The union posted this today:
http://www.cupw.ca/en/labour-code-and-strikes"Based on the provisions of the Canada Labour Code, there are three possible options available to us.
The parties could agree in writing to extend the 60-day period that the strike vote is valid for. This would allow negotiations to continue and we would retain our right to strike. Should CPC not agree to extend the period, then we may have no other choice than to issue a 72-hour notice of strike action on or before August 25, 2016.
If we do not use one of the above options by August 25th, then our strike vote mandate is no longer valid and we would have to hold another strike vote to have the ability to issue a 72-hour notice of strike action."