A panel of U.S. judges on Monday seemed likely to rule that Amazon.com and Elon Musk's SpaceX were too quick to bring their challenges to the National Labor Relations Board's structure to an appeals court.

Amazon and SpaceX are seeking to hamstring the National Labor Relations Board, asking a court to declare its processes for upholding labor law unconstitutional. But judges on a three-person panel appeared skeptical when the companies presented their arguments Monday.

Amazon and SpaceX are just among the rising number of companies that have opted to challenge the labor agency's structure. Lawsuits against the NLRB have been filed around the country, stating that a number of the processes violated U.S. Constitution. The case of Amazon and SpaceX are just among those that already reached the appellate court.

Judges Priscilla Richman, James Graves, Jr, and Irma Carrillo Ramirez took issue with the timelines of both the appeals from Amazon and SpaceX, with concerns that actions taken in neither case rose to the level of effective denial that merited an appeal to their court.

The oral arguments represented the latest legal attack from corporations against the 89-year-old National Labor Relations Board, buoyed by the U.S. Supreme Court's ruling this year in SEC v. Jarkesy.

Amazon and SpaceX face dismissal of NLRB challenges as judges question premature appeals over alleged labor law violations.

SpaceX and Amazon are asking the Fifth Circuit Court of Appeals to find the National Labor Relations Board unconstitutional. The federal agency is tasked with enforcing workers' right to organize.