Sen. Jeff Sessions (R-Ala.) was on “The Kelly File” tonight, where he slammed the Obama administration’s immigration plans, which were reported earlier this evening on Fox News.

As part of the 10-point plan, up to 4.5 million illegal immigrants living with their American born kids would be allowed to stay in the U.S., an expansion of deferred action.

Sessions recently co-wrote a letter to Senate Majority Leader Harry Reid, urging him to block executive action from the president that would amount to “amnesty.”

“The president has no authority to do this,” he said. “It’s against the law.”

Sessions said that immigration officers have said that if these plans goes through, it will be “almost impossible” to enforce the law.

“This is action unilaterally by one person, the president of the United States, to legalize millions that Congress has explicitly refused to do.”

He added that "executive amnesty" is really "a threat to constitutional order."

Watch more above.