Business groups will again sue the National Labor Relations Board (NLRB) over a controversial rule they say will speed up union elections and give organizers the upper hand in the workplace, sources say.

The NLRB last year reissued what business groups refer to as the “ambush” or “quickie” election rule, after it was originally struck down in federal court. But business groups complain the rule does not give them enough time to prepare for union elections.

After successfully challenging the original rule in federal court, business groups are hoping for a similar outcome this time around.

The Coalition for a Democratic Workplace, which includes the Chamber of Commerce, National Association of Manufacturers, National Retail Federation, and Society for Human Resource Management, is preparing to file a federal lawsuit against the NLRB as early as Monday afternoon.

“That’s in the works, and we’re pretty close to filing,” a source who is a party to the lawsuit told The Hill.

The business groups are seeking to roll back what they see as one of the most devastating regulations to come from the NLRB during the Obama administration. They say the rule would not only leave management with little time to prepare for an election, but would also rush employees to make a decision.

Currently, it takes an average of 38 days to hold a union election, according to the NLRB.

But business groups speculate that, under the new rule, elections could happen in as few as 10 days.

“Shortening the time frame before an election robs employees of the ability to gather the facts they need to make an important and informed decisions like whether or not to join a union and denies employers adequate time to prepare,” Jay Timmons, president and CEO of the National Association of Manufacturers, said when the rule was finalized last month.

But labor officials say the new rule will prevent management from unnecessarily delaying union elections.

“[This] means corporate bosses will have fewer opportunities to cheat you out of your right to join together,” SEIU President Mary Kay Henry said.

A federal court overturned an identical NLRB rule a few years ago for procedural reasons, because the rule came from a board that did not have a full quorum. Now that the NLRB is fully staffed, experts say it is less likely that a court will overturn the rule again.

The NLRB reintroduced the rule last February and finalized it in December.