A US federal judge has halted President Donald Trump’s latest attempt to block international students from coming to Harvard University.

The temporary restraining order issued late Thursday (5) by US District Judge Allison Burroughs comes hours after the university urged the judge to step in on an emergency basis to block a proclamation Trump signed a day earlier that suspends international visas for new students at the nation’s oldest and wealthiest university. Foreign students make up roughly a quarter of the school’s student body.

The brief order from Burroughs said if she didn’t intervene now, the school would “sustain immediate and irreparable injury before there is an opportunity to hear from all parties” over the challenge to Trump’s edict. The judge said her order “shall remain in effect until further order of this Court.”

Burroughs, an appointee of former President Barack Obama, set a hearing for mid-June to hear arguments over whether she should block Trump’s proclamation indefinitely.

Harvard’s request to block Trump’s ban amended an existing lawsuit over the administration’s move to end Harvard’s ability to enroll international students, which initially prompted the judge to stop the administration from revoking Harvard’s student visa program.

The amended lawsuit claimed Trump’s proclamation violated the First Amendment by temporarily blocking the entry of nearly all new international Harvard students under visas most use to study at US universities or participate in academic exchange programs.

Trump’s proclamation directed the Secretary of State “to consider revoking” the visas – known as F, M and J visas – for current Harvard students who meet the proclamation’s “criteria,” the White House said in a statement.

“With the stroke of a pen, the DHS Secretary and the President have sought to erase a quarter of Harvard’s student body, international students who contribute significantly to the University and its mission and the country,” the amended complaint reads.

“Without its international students, Harvard is not Harvard,” it says.

The visa program, which allows international students “to enter the United States on nonimmigrant visas to enroll at Harvard and thousands of other schools, have boosted America’s academic, scientific, and economic success and its global standing,” the lawsuit says.

In its amended lawsuit, Harvard rebutted claims by the White House that the proclamation is an attempt to “safeguard national security” and said it represents “a government vendetta against Harvard.”

“It escalates and intensifies the campaign of retaliation in violation of the First Amendment,” the amended suit reads. “… Just as the revocation unconstitutionally intrudes on academic freedom, the Proclamation unconstitutionally intrudes too.”

Trump’s proclamation hinges on a statute that gives the president authority to protect the nation from “any class of aliens whose entry would be detrimental” to the interests of the US, according to the document. But Harvard argues Trump is not suspending entry for any such class: “To the contrary, nonimmigrants may enter the country unabated, as long as they do not attend Harvard,” the lawsuit reads.

In a statement to the university community on Thursday, Harvard President Alan Garber said the proclamation is “yet another illegal step taken by the Administration to retaliate against Harvard.”

Harvard’s international community, Garber said, “make outstanding contributions inside and outside of our classrooms and laboratories, fulfilling our mission of excellence in countless ways.” The institution will “celebrate them, support them, and defend their interests as we continue to assert our Constitutional rights,” he added.