A union vote among British Columbia port workers is underway to determine the fate of a deal with employers that could bring their long-running industrial dispute to an end. The International Longshore and Warehouse Union Canada is holding its vote from 6 a.m. to 6 p.m. PT Thursday and Friday to decide whether to ratify the agreement recommended by negotiators. Rejection would raise the prospect of more federal involvement in the case, with the Canada Industrial Relations Board directed to impose a deal or binding arbitration on both sides if a negotiated resolution can’t be reached. …The union in the port dispute had voted down a previous agreement a week ago in another full membership vote, but no strike action has been taken since a brief stoppage on July 18.