Three members of coal producer Massey Energy's board of directors have narrowly survived attempts to oust them after the deadliest mine disaster in 25 years, opponents said Tuesday.

Preliminary results indicate that Massey board members Dan Moore, Baxter Phillips Jr. and Richard Gabrys escaped removal by margins of less than 2 percentage points each, according to the CtW Investment Group, which manages pension funds for about 6 million union workers and holds a small percentage of Massey stock.

CtW has called for the board to rein in Massey CEO Don Blankenship, blaming his "confrontational" approach to mine safety regulators for the April 5 explosion at the Upper Big Branch coal mine in West Virginia that killed 29 workers. It called Tuesday's vote "a clear demand for new directors who will make needed changes in company leadership."