After months of idle threats, a powerful trucking industry group said it plans to file a lawsuit next week against the ports of Los Angeles and Long Beach in an attempt to stop their controversial truck replacement programs.

Curtis Whalen, an executive with the American Trucking Association who has lobbied port leaders to change some of the more burdensome elements of the sweeping clean-air plan, said his group will file a lawsuit in Los Angeles federal court as early as July 28. Industry leaders said that under the plan, the ports can dictate standards for the trucking firms, which in effect would regulate an industry that has long operated freely.

“It’s a federally deregulated industry, which we don’t believe a local harbor commission can reregulate,” Whalen said.

The twin ports floated a plan more than a year ago that would fund the replacement of the roughly 16,800 short-haul diesel trucks in San Pedro Bay with cleaner burning models, including those that run on clean diesel or alternative fuels. Port officials said the $2.2 billion program, which aims to reduce diesel truck emissions by 80 percent, is essential to help stem the dangerous levels of toxic emissions generated by port operations.

The ports have weathered a storm of criticism from trucking companies, but port leaders believe they are on firm legal ground. Both ports declined to comment on the specific allegations of the trucking group, but the Port of Los Angeles released a statement to the Business Journal saying the program is defensible.

“A legal analysis was done by the ports, concluding they have the legal authority for the program. The details of the two ports’ legal analyses are confidential,” the port said.

But trucking companies said the ports have overstepped their bounds by putting restrictions on who can and cannot operate in the ports. For example, the ports will be able to verify a trucking company’s financial standing in order to let the trucking firm transport cargo at the ports. The trucking group claims that violates federal interstate commerce laws by restricting companies from operating their businesses freely.

The Port of Los Angeles went a step further by ending the now-common practice of independent driver contracting and requiring the companies to hire employee drivers – a provision backed by union officials and Los Angeles Mayor Antonio Villaraigosa that critics said will open the door for driver unionization. Trucking companies have said that would force them to radically change the way they do business and may result in many trucking companies going out of business.

“L.A. is much worse than Long Beach, but they both have problems,” said Whalen.

Both ports plan to begin phasing in a ban of the oldest trucks Oct. 1, but experts believe the expected lawsuit could be severely disruptive to the program.

Su Ross, chair of the international trade practice for Los Angeles law firm Mitchell Silberberg & Knupp LLP, said such a lawsuit will likely result in an injunction blocking the program.

“If that happens, it puts everything on hold until the case is decided or the injunction is lifted,” she said, adding that the truck replacement program will likely be “delayed at least a year or maybe longer.”

As far as the merits of such a lawsuit, Ross, who is not affiliated with the lawsuit but who has followed the port plan, said it appears as though the trucking association will have a legal leg to stand on. The group is saying that the ports cannot impose restrictions on motor carriers that govern the routes, rates or services offered by the private companies.