Secretary of the Interior Ryan Zinke slammed Democratic Rep. Raúl Grijalva as a drunk after the congressman threatened to probe his department when Democrats take the House majority in January.

Grijalva is the likely incoming chairman of the House Natural Resources Committee and called for Zinke's resignation in an op-ed.

Secretary of the Interior Ryan Zinke slammed a Democratic congressman, labeling him as a problem drinker on Friday in response to an op-ed calling for his resignation.

Arizona Rep. Raúl Grijalva, who is slated to serve as the next chairman of the House Natural Resources Committee when the 116th Congress convenes in January, wrote an op-ed for USA Today outlining why he believes Zinke is unfit to helm the Department of the Interior.

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"Ryan Zinke needs to resign immediately as Secretary of the Interior," he wrote. "I take no pleasure in calling for this step, and I have resisted it even as questions have grown about Mr. Zinke’s ethical and managerial failings. Unfortunately, his conduct in office and President Donald Trump’s neglect in setting ethical standards for his own cabinet have made it unavoidable."

Grijalva also pledged to vigorously investigate and probe Zinke's department in the new year.