The Justice Department has warned the White House that President Trump’s national emergency declaration will most likely be blocked by courts, a report said Thursday.

The department said the declaration is nearly certain to be blocked, at least on a temporary basis, preventing the president from accessing billions of dollars for his border wall, according to ABC News.

The White House has been preparing to mount a legal effort against possible court challenges.

The emergency order would free up funds that Trump can use to build a massive wall across the US border with Mexico.