The Teamsters union says it was told by FMCSA officials that the government agency intends to grant authority on Sept. 1 for Mexican trucks to drive beyond the 15-mile border zone throughout the entire United States.

"What a slap in the face to American workers -- opening the highways to dangerous trucks on Labor Day weekend, one of the busiest driving weekends of the year," said Teamsters General President Jim Hoffa.

Congress recently voted to block the program until the DOT's Inspector General has finished the project. The IG has reportedly finished a preliminary audit, finding that the agency has improved the safety program, but a second report examining the data the FMCSA will use to monitor Mexican trucks has still not been released. That second report is expected by the end of the week.

The Teamsters, along with the Sierra Club, Public Citizen, and the Owner-Operator Independent Drivers Association have filed a request for an injunction against the FMCSA's plan to proceed this weekend.

"I am honestly stunned by the Administration's contempt toward the American public, Congress and the rule of law," said Todd Spencer, executive vice-president of OOIDA.

"They are determined to open our highways to Mexico-domiciled trucking companies regardless of the public’s concerns and what’s in the law books. Congress responded to concerns about the safety and security implications of this pilot program. It is truly amazing that the Administration is choosing to ignore Congress and the people they were elected to represent."

The groups insist the government create a program that yields statistically valid findings; show that U.S. trucks have the same right to travel in Mexico that Mexican-domiciled trucks have in the U.S.; and reveal the inspection results for motor carriers allowed to drive beyond the border zone.

In a statement, FMCSA said it is reviewing the suit and will respond to the court shortly. The agency added that the lawsuit is without merit and that its program will benefit consumers by reducing the costly practice of requiring cross-border shipments to be transferred onto separate trucks operated by different drivers.