BNSF Railway, one of the country’s largest freight companies, has asked a federal court to block thousands of union members who help transport agricultural and industrial goods nationwide from striking over a change in attendance policy set to take effect Feb. 1.

Both sides were in court Monday, but U.S. District Judge Mark T. Pittman of the Northern Texas District didn’t rule on the motion seeking a temporary restraining order.

In its lawsuit, BNSF said the two unions representing 17,000 workers would be in breach of their obligations because the nature of the dispute doesn’t rise to a level that would justify a work stoppage.

BNSF characterized the disagreement as a “minor dispute” over the interpretation of existing rights under its collective bargaining agreements with the unions, which means the matter must be resolved by negotiation or arbitration, not by striking, according to court records.

“Any disruption of BNSF’s operations would therefore have a serious impact on interstate and international commerce,” the company said in the Jan. 13 court filing.

The freight rail company hauled 4 million carloads of industrial products and agricultural commodities in 2020, according to company officials.

Members of the Brotherhood of Locomotive Engineers and Trainmen and the Transportation Division of the International Association of Sheet Metal, Air, Rail and Transportation Workers have threatened to strike if the policy goes into effect next week.

They claim the new policy constitutes a unilateral change and a violation of their collective bargaining agreements that could be considered a “major” dispute. Neither the company nor the unions have publicly disclosed exactly what the changes are.

But the unions said on their websites that the new policy is a points-based system that penalizes employees — who in many cases have no assigned days off — whenever they take time off.

“This unprecedented BNSF policy repudiates direct and clear contract language, and in application, will attempt to force our members to report for duty without regard for their medical condition as we struggle to come out of a pandemic,” union presidents Dennis Pierce and Jeremy Ferguson said in a joint statement.

They said the changes also conflict with collective bargaining agreements the railway has with other unions.

BNSF, which has more than 30,000 employees, operates more than 30,000 miles of track in 28 states while serving thousands of industrial and commercial customers, dozens of whom have no other access to rail transportation, according to court records.