Tensions between Virginia Gov. Bob McDonnell and the board overseeing construction of the $6 billion Dulles rail project escalated this week when McDonnell ordered that a union official be removed from the board.

McDonnell ordered the removal of Dennis Martire, a vice president of Labors’ International Union of North America and an appointee of former Democractic Gov. Tim Kaine, from the Metropolitan Washington Airports Authority board. Martire filed a lawsuit in U.S. District Court Thursday to fight the order.