The departure of the 1.4 million member UFCW from the labor federation means the AFL-CIO is losing more than 4 million of its 13 million members.
Earlier this week, the UFCW joined the Teamsters, Service Employees International Union and Unite Here, a group of textile, restaurant and hotel employees, in boycotting the AFL-CIO convention in Chicago. The Teamsters and service workers announced then that they were leaving the AFL-CIO. Unite Here is still considering its next step.
During the convention, AFL-CIO President John Sweeney was re-elected to another term and he pledged to make changes to address the woes of organized labor. But the departing unions say those changes are insufficient.
"The world has changed and workers' rights and living standards are under attack," UFCW President Joe Hansen said in a letter delivered to Sweeney on Friday. "Tradition and past success are not sufficient to meet the new challenges."
The departure of the unions has frustrated labor federation officials.
"The UFCW leadership decision to leave the AFL-CIO, especially when working people are up against the most powerful, anti-worker corporate and governmental forces in 80 years, is a tragedy for working families," said Lane Windham, spokesperson for the AFL-CIO. "Only union's enemies win when unions split our strength."