A federal judge in New Hampshire Thursday issued a preliminary injunction against President Donald Trump’s executive order that would rewrite the constitutional right to birthright citizenship, and granted a class certification to infants who would be affected by the order.

Trump’s executive order, signed in January, seeks to deny citizenship to children who are born to people who are living in the U.S. illegally or temporarily. It is part of the hard-line immigration agenda of the president, who has called birthright citizenship a “magnet for illegal immigration.”