CHARLESTON, W.Va. — About 12,500 union coal miner retirees and their dependents are receiving letters warning them they’ll lose their health benefits on Dec. 31 without congressional action.

The Patriot Voluntary Employee Beneficial Association shipped the letters last week. The United Mine Workers of America retirees worked at mines run by now-bankrupt Patriot Coal and its predecessors.

The letters say the money will run out Dec. 31 unless Congress passes a bill expected to come up after the Nov. 8 election.

It would protect health care and pension benefits for about 120,000 former coal miners and their families amid the industry’s decline. Supporters call it a life-saving measure honoring a 70-year-old promise from the federal government.

Some Republicans, including Senate Majority Leader Mitch McConnell of Kentucky, are wary of bailing out unionized workers.

This story corrects that retirees receiving letters worked for Patriot and its predecessors.