Haywood Gilliam a U.S. District Court Judge for the Northern District of California, temporarily blocked the Trump administration’s plan to spend billions to construct a wall on the U.S.-Mexico border.

Judge Gilliam’s ruling halts the administration from using the reallocated funds for projects in specific areas in Texas and Arizona.

“In short, the position that when Congress declines the Executive’s request to appropriate funds, the Executive nonetheless may simply find a way to spend those funds “without Congress” does not square with fundamental separation of powers principles dating back to the earliest days of our Republic,” wrote Gilliam in his ruling.

Haywood Stirling Gilliam Jr. was nominated by President Obama on September 8, 2014 to serve as U.S. District Judge for the Northern District of California.