A federal judge has barred the Trump administration from deporting immigrants on the basis of the Alien Enemies Act of 1798, ruling Thursday that the use of the World War II-era policy to banish alleged Tren de Aragua gang members from the country without due process is illegal.

President Donald Trump’s invocation of a wartime power to summarily deport Venezuelan nationals to El Salvador was “unlawful,” a federal judge ruled Thursday, blocking the administration from further deportations under the Alien Enemies Act of 1798.