A US federal judge has blocked the enforcement of a new executive order limiting the number of people eligible for birthright citizenship that President Donald Trump issued after the Supreme Court rejected his previous effort.

District Judge Deborah Boardman granted a preliminary injunction in Maryland, at the request of immigrant advocates, who had secured a ruling from her last year blocking the administration from enforcing the initial 2025 order curtailing the right.

On 30 June, the Supreme Court rejected that initial effort to end birthright citizenship for children whose parents were not American citizens or legal permanent residents, known as green card holders, finding it violated the citizenship clause of the US Constitution’s 14th Amendment.

The clause, which was the focus of the court’s 6-3 ruling in Barbara v Trump, confers citizenship to those born in the United States who are “subject to the jurisdiction thereof”.

Following that decision, President Trump signed a new order on 6 August that took particular aim at “birth tourism,” in which women travel to the US to give birth so their children ‌can ⁠obtain automatic citizenship.

Citizenship would also be denied to children if one of their parents works for foreign governments in the US, engages in fraud or a commercial transaction to obtain citizenship, or is classified as an “alien enemy”.

After he signed that order, legal teams pursuing a class action on behalf of babies who would be deprived citizenship under the 2025 order asked Judge Boardman to block enforcement of the president’s newest attempt and ensure their clients’ citizenship continued to be honoured.

The judge, an appointee of former president Joe Biden, agreed to do so, saying the latest order “is almost certainly unconstitutional as applied to the certified class for the simple reason that the Supreme Court in Barbara already decided that the children in the class are citizens at birth”.

“The Supreme Court has spoken: Children in the certified class are ‘citizens at birth,'” she wrote.

Her order bars agencies, including the Department of State, the Department of Homeland Security and the Social Security Administration, from taking any action to interfere with, deny or fail to recognize citizenship of children covered by the class action.

The White House did not immediately respond to a request for comment.

The plaintiffs include the immigrant rights groups CASA and Asylum Seeker Advocacy Project, which last year convinced Judge Boardman to become one of four lower-court judges to block President Trump’s initial order, before the Supreme Court ruling.

“Immigrant families should not have to come back to court to defend the rights of their US-born children and others whose citizenship is being questioned by a new executive order,” co-executive director of the Asylum Seeker Advocacy Project Conchita Cruz said in a statement.

Department of Justice lawyers argued that an injunction was inappropriate in this case, as the order was more narrow than the sweeping one the plaintiffs first sued over.

They also described the legal action as premature, saying federal agencies had yet to issue the necessary public guidance detailing how the president’s directive would be implemented, which they are expected to do by Saturday.

Any legal challenge should wait until then, the administration argued.

But Judge Boardman decided that an injunction was needed now, saying that while the justice department claimed the order would be applied only prospectively, by its plain terms it “applies to all children who meet its criteria, regardless of when they were born”.

“This Court must, once again, preliminarily enjoin enforcement of the President’s most recent attempt to strip the right to citizenship from them,” she wrote.

While Judge Boardman blocked enforcement of the order, she said that agencies could still issue guidance on how it would be implemented.

Earlier this week, it was reported that the state department had drafted proposed guidance requiring parents applying for passports for their children to provide proof of their own citizenship or immigration status to implement that executive order.