Representing 384,000 Union Plumbers, Fitters, Welders and Service Technicians. Tweets from GP McManus signed -MM LABOR UNION TO PROMOTE THE WELFARE OF ITS MEMBERS BY SECURING ADEQUATE WAGES, WORKING CONDITIONS, AND OPPORTUNITIES FOR EMPLOYMENT. TO ENCOURAGE ITS MEMBERS TO SAFEGUARD AND PROMOTE THE PRINCIPLES OF FREE COLLECTIVE BARGAINING, AND PROTECT THE JUSRISDICTION OF THE WORK OF THE UNITED ASSOCIATION.