(CNN) Interior Secretary Ryan Zinke on Friday morning labeled as a drunk the man who is expected to be his chief foe on Capitol Hill, an attack that echoes President Donald Trump's own name calling style and sets the stage for tense showdowns on Capitol Hill when Democrats take the House in January.
Zinke's tweet came in response to top Natural Resources Committee Democrat Rep. Raul Grijalva calling on the interior secretary to resign in a USA Today op-ed, citing Interior Department inspector general investigations, one of which was referred to the Justice Department.
In his response, Zinke did not address Grijalva's allegations but instead said that it was "hard for (Grijalva) to think straight from the bottom of the bottle."
"This is coming from a man who used nearly $50,000 in tax dollars as hush money to cover up his drunken and hostile behavior. He should resign and pay back the taxpayer for the hush money and tens of thousands of dollars he forced my department to spend investigating unfounded allegations," Zinke wrote in the tweet.
After Zinke's tweet, Grijalva responded through a statement from his office: "The American people know who I'm here to serve, and they know in whose interests I'm acting. They don't know the same about Secretary Zinke."
The op-ed and the tweet underscore the tense relationships expected to develop as Democrats take control of the House in January and launch a series of investigations into the Trump administration.
Grijalva has long expressed concerns about Zinke, but in the minority had few tools at his disposal to call the secretary before the committee or demand answers to questions he had about national monuments, endangered species for ethical questions into the secretary. That is all about to change.
In his op-ed, Grijalva called on Zinke to resign saying "I take no pleasure in calling for this step, and I have resisted it even as questions have grown about 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," he said.
In responding to the op-ed, Zinke's attack on Grijalva's character did not include specifics, but the Washington Times reported that in 2015, Grijalva reached a settlement with a woman in his office to pay $48,000 after, according to the Times, the woman complained that Grijalva was often under the influence of alcohol, creating a hostile work environment. Grijalva vehemently denied that he drank on the job or fostered any kind of hostile work environment. He said in an op-ed for Tuscon.com that said "I do not work while drunk and have never had a hostile workplace environment."
However, he said "agreeing to a severance package made it possible for the Committee to move forward with its operations as quickly as possible and for the former employee to quickly begin seeking new opportunities."
He noted that under a non-disclosure agreement he could not elaborate on the complaint.
Expected to chair natural resources, Grijalva said he planned to continue digging into Zinke.
"Should I chair the committee in January, as I hope to do, those questions will only intensify as part of my and my colleagues' legitimate oversight duties. If Mr. Zinke stays, stonewalling in the belief that a cabinet secretary answers only to Trump would be a mistake," Grijalva wrote in the op-ed.
The inspector general's office at the Department of Interior still has two active investigations into Zinke surrounding whether or not the Department of Interior improperly blocked a casino deal in Connecticut and into conversations Zinke had with then-Halliburton Chairman David Lesar about a development project back in Zinke's hometown of Whitefish Montana.
In October, CNN reported that the inspector general's office had referred Zinke for investigation at the Justice Department and that the Department of Justice was investigating the interior secretary.
Zinke said he has not been contacted by the Justice Department.
"They haven't talked to me. It will be the same thing as all the other investigations. I follow all rules, procedures, regulations and most importantly the law. This is another politically driven investigation that has no merit," Zinke told CNN.