(Bloomberg) -- The US Supreme Court rejected a challenge to the country’s largest guest-worker program, which lets more than 100,000 people work temporarily in the US after getting their degrees. 

The justices said they won’t hear arguments from a technology-workers union that said the Optional Practical Training program isn’t authorized under federal immigration law. 

The program lets people on student visas stay for as long as three years after graduation to get on-the-job training if it’s either required or recommended by their school. The rules have support of the US Chamber of Commerce and other business groups, which joined the Biden administration in defending the system. 

In upholding the program, a federal appeals court in Washington said every president since Harry Truman in the late 1940s has interpreted federal immigration law as letting foreign students stay in the country to get practical training. The lawsuit targeted the version of the program the federal government put in place in 2008. 

The group pressing the lawsuit, the Washington Alliance of Technology Workers, said the program is being used to circumvent limits on the number of foreigners who can get work visas under the separate H-1B program. 

The union had backing from Republican elected officials and the conservative American First Legal Foundation.

The case is Washington Alliance of Technology Workers v. Department of Homeland Security, 22-1071.

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