The head of the largest public employee union in the United States is stepping down, according to an article published Thursday.

Gerald McEntee will step down as head of the American Federation of State, County, and Municipal Employees (AFSCME) after holding the position for the past 30 years, according to The American Prospect monthly magazine. McEntee told top-level members of AFSCME that he would step down, but it is unclear when.

“President McEntee called me to let me know he has decided to retire and will not be running for re-election. We did not discuss his reasoning for this decision, but I had heard his health has not been the best lately,” AFSCME Indiana leader David Warrick said, according to the publication.

AFSCME is the largest arm of the AFL-CIO, with more than 1.4 million members. The union has long been a supporter of Democratic campaigns and helped President Barack Obama’s presidential campaign in 2008.