Sen. Rand Paul, who has joined with four other GOP senators against approving President Trump’s national emergency declaration, predicted that the Supreme Court will strike down the action because it violates the “will of Congress.”

“Without question, the president’s order for more wall money contradicts the will of Congress and will, in all likelihood, be struck down by the Supreme Court,” Paul wrote in an op-ed for Fox News published late Sunday.

He went on to say that he believes Trump’s picks to the court — Brett Kavanaugh and Neil Gorsuch — “may rebuke him on this.”

Trump declared a national emergency last month in a maneuver that would allow him to siphon funds from the military construction budget to pay for a wall on the southern border, a signature issue of his presidential campaign.

The declaration came after Congress refused to authorize the $5.7 billion in funds Trump demanded for the barrier — appropriating only $1.375 billion.

“Congress clearly expressed its will not to spend more than $1.3 billion and to restrict how much of that money could go to barriers,” the Kentucky Republican wrote in the piece.

“Therefore, President Trump’s emergency order is clearly in opposition to the will of Congress.”

Paul recalled that he and Trump objected to President Barack Obama’s use of executive power in 2014 to expand the Deferred Action for Childhood Arrivals program and said he has to view Trump’s order the same way.

“I would literally lose my political soul if I decided to treat President Trump different than President Obama,” Paul said, adding that he supports Trump’s views on immigration.

“I supported his fight to get funding for the wall from Republicans and Democrats alike, and I share his view that we need more and better border security,” he wrote. “However, I cannot support the use of emergency powers to get more funding, so I will be voting to disapprove of his declaration when it comes before the Senate.”

Three other Republicans in the chamber — Thom Tills of North Carolina, Susan Collins of Maine and Lisa Murkowski of Alaska — also said they won’t back Trump’s emergency declaration.

If those four join with all the 47 senators who caucus with the Democrats, there would be a bipartisan majority to block the declaration, leaving Trump with the choice to veto the legislation, which has already passed the House.

But Congress does not appear to have the two-thirds majority needed to override his veto — meaning Trump’s declaration could stay in place.