A federal judge on Wednesday temporarily blocked the Trump administration from pulling legal protections from hundreds of thousands of people who entered the United States through Biden-era programs, ordering the government to restart processing applications for migrants who are renewing their status.

In a sweeping order that extended to Ukrainians and Afghans, as well as military members and their relatives, the judge, Indira Talwani of Federal District Court in Massachusetts, wrote that the Trump administration’s categorical termination of legal pathways for those groups was probably unlawful and had the potential to sow discord across the country.

The decision is a major victory for civil and immigrant rights groups that had sued to stop the administration amid a wider campaign by President Trump to strip legal status from a variety of groups living, working and studying in the country on a temporary basis.

Judge Talwani wrote that the overarching campaign to strip the protections from those who had already been granted them represented a major escalation by the Trump administration that would cause chaos once the programs were wound down.

“This court emphasizes, as it did in its prior order, that it is not in the public interest to manufacture a circumstance in which hundreds of thousands of individuals will, over the course of several months, become unlawfully present in the country, such that these individuals cannot legally work in their communities or provide for themselves and their families,” Judge Talwani wrote. “Nor is it in the public interest for individuals who enlisted and are currently serving in the United States military to face family separation, particularly where some of these individuals joined the military in part to help their loved ones obtain lawful status.”

As part of the order, Judge Talwani, who was appointed by President Barack Obama, also moved to certify all those affected as a class, extending blanket protections temporarily to those in several programs pending a final decision in the case.

They included Afghans who worked with the U.S. military during 20 years of war in Afghanistan; Ukrainians fleeing violence after Russia’s full-scale invasion in 2022; and those in a family reunification program that allowed migrants from some Central and South American countries to join their family members in the United States while awaiting a visa.

While broad, the certification applied primarily to those who had already received humanitarian parole and were working to extend their status, receive another benefit or avail themselves of another legal pathway. It did not apply to individuals who had left the United States voluntarily and were living abroad.

The challenge was filed in response to an executive order by Mr. Trump on Jan. 20 that directed the government to end “all categorical parole programs” set up during the Biden administration. The termination of the initiatives is part of a wider push by the Trump administration to expand the definition of who is removable from the United States as it seeks to make good on Mr. Trump’s campaign promise to carry out mass deportations.

Though the decision on Wednesday is likely to be challenged, immigration advocates and lawyers lauded the move, calling it a step in the right direction and significant relief for families, some of whom had already lost protections and their ability to work.

Guerline Jozef, executive director and founder of the Haitian Bridge Alliance, one of the plaintiffs in the case, said in a statement that the news “should serve as a reminder that when we fight together, we win.”

“Whether we come from Ukraine or Haiti, Afghanistan or Nicaragua, Venezuela, Cuba, all those with humanitarian parole should have the freedom to live and work peacefully in their adopted communities and with their families,” she said.