A federal judge in Austin on Thursday halted a new state law that would allow Texas police to arrest people suspected of crossing the Texas-Mexico border illegally.

The law, Senate Bill 4, was scheduled to take effect Tuesday. U.S. District Judge David Ezra issued a preliminary injunction that will keep it from being enforced while a court battle continues playing out. Texas is being sued by the federal government and several immigration advocacy organizations.

Ezra said in his order Thursday that the federal government “will suffer grave irreparable harm” if the law took effect because it could inspire other states to pass their own immigration laws, creating an inconsistent patchwork of rules about immigration, which has historically been upheld as being solely within the jurisdiction of the federal government.

“SB 4 threatens the fundamental notion that the United States must regulate immigration with one voice,” Ezra wrote......

“This decision is a victory for all our communities as it stops a harmful, unconstitutional, and discriminatory state policy from taking effect and impacting the lives of millions of Texans," she said. "Local officials should not be federal immigration agents, and our state should not be creating its own laws that deny people their right to seek protection here in the U.S."

David Donatti, senior staff attorney at the ACLU of Texas, said the ruling is an "important win for Texas values, human rights, and the U.S. Constitution."

"Our current immigration system needs repair because it forces millions of Americans into the shadows and shuts the door on people in need of safety. S.B. 4 would only make things worse," he said. "Cruelty to migrants is not a policy solution.”