A coalition of business groups on Monday sued to block a massive new regulation by the National Labor Relations Board that speeds up and simplifies the process for holding union elections.

The U.S. Chamber of Commerce, the Coalition for a Democratic Workplace, the National Association of Manufacturers, the National Retail Federation and the Society for Human Resource Management filed suit against the NLRB in U.S. District Court for the District of Columbia. The groups argue that the so-called “ambush election” rule is unconstitutional, arbitrary and capricious and goes against congressional intent.