Washington DC - The Biden administration has warned it will sue Texas if the state enforces an extreme anti-migrant measure signed into law this month by Republican Governor Greg Abbott.

Senate Bill 4, known as the "Show Me Your Papers" law, would empower state and local law enforcement to detain, arrest, and deport people without documentation.

The bill's passage sparked immediate backlash from immigrants' rights groups, who warn that its provisions will lead to even more racial profiling and militarization of border communities.

The American Civil Liberties Union, ACLU of Texas, and Texas Civil Rights Project have already filed a lawsuit on behalf of the Las Americas Immigrant Advocacy Center, American Gateways, and the County of El Paso, arguing that SB4 is unconstitutional and breaches federal immigration law.

Now, the US Justice Department is adding pressure on the Texas state government not to follow through on implementing the measure.

In a new letter to Abbott, obtained by the Houston Chronicle, Principal Deputy Assistant Attorney General Brian M. Boynton wrote, "Because SB 4 is unconstitutional and will disrupt the federal government's operations, we request that Texas forbear in its enforcement."

If the governor does not provide confirmation by January 3, "the United States intends to file suit to enjoin the enforcement of SB 4," Boynton said.

Texas Congressman Greg Casar has celebrated the Biden administration's move, saying in a statement, "This new 'Show Me Your Papers' law is unconstitutional and out of line with Texas values. Instead of working to improve public schools, or health care, or the economy, Abbott puts all his energy – and billions of dollars – into extreme anti-immigrant laws."

"Asking local police to hunt down Texans who look like immigrants doesn’t make us safer: in fact, it takes police away from investigating real crime," he added. "The federal government must block this unconstitutional anti-immigrant policy before it takes effect."

SB 4 is set to go into effect on March 5, 2024, unless action is taking to delay or prevent its enforcement.