THE CANADIAN PRESS/Jeff McIntoshTalking Points WestJet and the Canadian Union of Public Employees (CUPE) are in intense negotiations after CUPE issued a 72-hour strike notice, potentially impacting summer travel. Intense bargaining between WestJet and the union representing its flight attendants ratcheted up further on Thursday after CUPE issued a 72-hour strike notice, paving the runway for a possible airline shutdown during the busy summer travel season. The Canadian Union of Public Employees cancelled a news conference in Calgary on Thursday morning, saying it wanted to focus on hammering out a deal. AdvertisementWestJet responded to the union’s strike notice by issuing a 72-hour lockout notice. WestJet, flight attendants sign wind-down plan ahead of possible strikeFederal Transport Minister Steven MacKinnon said Wednesday that “talks are progressing” and he remained hopeful a new collective agreement could be negotiated.