A Miami federal judge on Monday blocked Florida from enforcing a new state law that prohibits governments from hiring companies with business ties to Cuba.

A temporary injunction, ordered by U.S. District Judge K. Michael Moore, prevents the law from taking effect on Sunday as scheduled. And it deals a blow to the politicians who backed the legislation, which was sponsored by Miami-Dade lawmakers, approved by a near-unanimous majority of the Legislature and signed by Gov. Rick Scott.

After an hour-long hearing late Monday, Moore ruled from the bench in favor of Odebrecht Construction, the Coral Gables-based subsidiary of a Brazilian engineering and construction giant.

“It’s not as if there isn’t some precedent there and there hasn’t been a run at this effort in the past,” the judge said, referring to previous failed legislative efforts to make it difficult to conduct business with Cuba.

Odebrecht USA sued the Florida Department of Transportation earlier this month over the new law, which would ban state and local government agencies from awarding future contracts worth at least $1 million to U.S. firms whose foreign-owned parent companies or affiliates conduct business in Cuba or Syria. A subsidiary of Odebrecht USA’s parent company is expanding the Cuban Port of Mariel.

Odebrecht said the state law would prevent it from bidding on $3.4 billion in FDOT contracts this year, and that the company had already suffered “irreparable harm” because the law spooked potential business partners and employees.

Though the judge’s order was directed at FDOT, it is highly unlikely that any other state or local government agency would try to enforce the law while the injunction is in place.

The judge agreed with Odebrecht’s contention that the law conflicts with the federal government’s power to set foreign policy. The state, Moore said, would “inject itself into foreign affairs matters, which are traditionally under the prerogative of the executive branch.”

Moore’s ruling, while temporary, foreshadows that he is likely to issue a permanent decision that the law is unenforceable. The judge wrote in his order that Odebrecht “has demonstrated a substantial likelihood of success with respect to its claims.” He did not set a new hearing date, and told the parties to work out a resolution.

In a statement, Odebrecht USA, which has been involved in some of South Florida’s most visible projects, including the Adrienne Arsht Center for the Performing Arts and AmericanAirlines Arena, said it was “very gratified” by Moore’s ruling.

“We are extremely proud of our 21-year track record of performance and community involvement in Miami-Dade County and throughout Florida,” the company said.

“We will continue to defend our right to serve the state of Florida and its local governments, and remain fully committed to complying with all local, state and federal law, and dedicated to working with our partners to provide outstanding service to each of our clients.”

FDOT’s attorney, Paul J. Martin, had argued that the state is allowed to set parameters for how to spend public money. He also made a complicated argument that the state law does not run afoul of federal law because the Florida statute does not allow anything that U.S. law prohibits.