DENVER – The U.S. Department of Transportation’s chief issued a stern warning on Monday, threatening to cut off $24 million in federal funds to Colorado. This move comes in response to what he described as the state’s sluggish handling of a significant breach of federal commercial driver’s license (CDL) regulations.

Transportation Secretary Sean Duffy highlighted findings from a national audit conducted in October, which revealed that approximately 22% of commercial licenses granted by Colorado were issued unlawfully. A large number of these licenses were given to immigrants, particularly Mexican nationals, contravening federal law.

Duffy criticized Colorado for its “slow walking” in addressing the issue, pointing out the state’s failure to conduct a comprehensive audit, accurately account for the drivers involved, or revoke the illegitimate licenses, despite being previously informed of their non-compliance.

The secretary emphasized that Colorado cannot selectively adhere to federal regulations, especially when public safety is at stake.

“Every day that passes allows unqualified, unvetted foreign truckers to jeopardize the safety of you and your family,” Duffy stated emphatically.

Further, Duffy warned that the Transportation Department possesses the power to entirely decertify Colorado’s CDL program if immediate corrective action is not taken by the state.

Colorado Gov. Jared Polis’ office did not immediately respond to emailed questions about the federal government’s allegations or the potential public safety concerns.

Polis, a two-term Democrat, has been at odds with the Trump administration in recent months. Tensions flared as recently as this past weekend when the Trump administration denied disaster declaration requests following wildfires and flooding earlier this year. Last week, Polis also criticized the administration’s plans to dismantle a federal climate research lab located in the state.

Colorado’s Division of Motor Vehicles has paused the issuance and renewal of term-limited non-domiciled CDLs and commercial learner’s permits indefinitely, The Denver Post reported last week. That pause is expected to remain in place pending an audit of all such licenses to ensure compliance with federal regulations.

Duffy has threatened federal highway funding for other states, too, in his effort to make sure truck drivers and bus drivers are qualified to either haul passengers or 80,000 pounds (36,000 kilograms) of cargo down the highway.

New York was the fourth state run by a Democratic governor to be called out publicly earlier this month. Questions also have been raised about similar practices in California, Pennsylvania and Minnesota.

Letters also have gone out from the agency to Republican-run Texas and South Dakota.

Duffy launched the review this summer, but it became more prominent after officials reported that a truck driver who was not authorized to be in the U.S. made an illegal U-turn and caused a crash in Florida that killed three people in August.

The rules on these licenses the Transportation Department is enforcing have been in place for years. According to the federal audit, it was discovered that in some instances states may not have even checked a driver’s immigration status before issuing a license.

Since Duffy began pressing the issue in California, that state has revoked some 21,000 commercial driver’s licenses that were issued improperly.