A federal judge has temporarily halted a Trump administration regulation that aimed to limit the duration of stays for foreign students, journalists, and exchange visitors, just one day before it was scheduled to take effect.

On Monday, a district judge in Massachusetts determined that the new policy would likely inflict “catastrophic” harm on the US economy and higher education system, dismissing the government’s argument that it was necessary for national protection.

The Trump administration’s rule, finalized in July, imposed a four-year cap on student and exchange visitor visas and a 240-day limit on journalists’ visas, excluding China. Under the now-delayed rule, media professionals from China were restricted to visas valid for 90 days.

The regulation, scheduled to take effect on Tuesday, permitted students and journalists to request extensions, but their approval was left to the discretion of Department of Homeland Security (DHS) officials, with no mechanism to challenge a denied extension.

Judge F. Dennis Saylor IV also dismissed the government’s argument that the relief should apply only to the plaintiffs rather than nationwide.

The preliminary injunction suspends enforcement of the new rule while the case proceeds in court. The plaintiffs encompass nearly 600 public and private institutions, but there are more than 5,000 higher-education institutions in the United States, the judge observed.

Limiting relief to the parties represented would require maintaining parallel regulatory regimes and making repeated and potentially inconsistent determinations of whether a particular student or institution falls within the scope of the order, Saylor ruled.

Several organisations, mainly from the higher education sector and labour unions, had approached the court seeking to have the rule annulled.

Harvard President Alan M. Garber described the rule as “odd,” noting that the four-year limit conflicted with the usual duration of a PhD programme. “A typical PhD programme generally takes at least six years, so setting four years as the visa cutoff is rather unusual,” Garber said in July.

But the DHS argued that the limits would help it curb fraud and make it easier to stop people from overstaying their visas.

The judge has also specifically noted the possibility that the now-blocked rule could be abused.

He noted that there is a clear risk that visas for foreign journalists who criticize the government especially officials within the Department of Homeland Security, will not be renewed.

He further stated that the tenuous link between the rule and its stated justifications raises valid concerns that its true objective may not be to protect national security and secure the borders, but rather to pursue other, undisclosed aims, such as increasing government control over academic institutions and the press, according to the judge’s ruling granting the preliminary injunction.