OTTAWA—A union representing about 9,000 Canadian Border Service Agency workers says its members’ employers have agreed to return to the bargaining table following a strike threat made earlier this week. The Public Service Alliance of Canada and its Customs and Immigration Union says the CBSA and Treasury Board Secretariat committed to resuming negotiations within hours of the strike threat. PSAC-CIU represents 5,500 border services officers, 2,000 headquarters staff and other workers at Canada Post facilities and in inland enforcement jobs. The union members have been without a contract for about three years and on Tuesday, agreed to strike as early as Aug. 6 if the two sides can’t reach an agreement. The union and the employers have been unable to agree on better protections for staff that the union argues would bring them in line with other law enforcement personnel across Canada and address a “toxic” workplace culture. The dispute …