Sen. Ron Johnson responded to a request for his account of White House meetings by providing an 11-page letter to Congress which declared “it is entirely possible” that Lt. Col. Alexander Vindman leaked information from President Trump’s Ukraine call.

The Wisconsin Republican sent the letter to the ranking Republicans on the House Intelligence and Oversight Committees, Rep. Devin Nunes of California and Rep. Jim Jordan of Ohio, on Monday on the eve of testimony by Vindman, a National Security Council official.

(Video: Fox News)

Johnson, the chairman of the Senate Foreign Relations Committee’s Europe subcommittee, slammed the House impeachment inquiry into Trump as an “effort to sabotage the Trump administration,” and cast doubts on the closed-door testimony Vindman gave to the House Intelligence Committee about what he heard when he listened in on the July 25 phone call Trump had with the newly-elected Ukraine president.

Vindman and Jennifer Williams, an aide to Vice President Mike Pence, are scheduled to appear before the House Intelligence Committee on Tuesday and in previous testimony expressed their concern over Trump’s call with Ukrainian President Volodymyr Zelensky, which led to the impeachment inquiry.

Vindman reportedly claims official transcript of Trump-Ukraine call omits damning parts https://t.co/9390cEbluj pic.twitter.com/BI3SWzVh0q — Conservative News (@BIZPACReview) October 30, 2019

Johnson, who attended Zelensky’s inauguration on May 20, recounted in his letter a conversation he had with Vindman.

“I had just finished making the point that supporting Ukraine was essential because it was ground zero in our geopolitical competition with Russia. I was surprised when Vindman responded to my point. He stated that it was the position of the NSC that our relationship with Ukraine should be kept separate from our geopolitical competition with Russia. My blunt response was, ‘How in the world is that even possible?’” Johnson wrote.

“I do not know if Vindman accurately stated the NSC’s position, whether President Trump shared that viewpoint, or whether Vindman was really just expressing his own view. I raise this point because I believe that a significant number of bureaucrats and staff members within the executive branch have never accepted President Trump as legitimate and resent his unorthodox style and his intrusion onto their ‘turf,’” he continued.

“They react by leaking to the press and participating in the ongoing effort to sabotage his policies and, if possible, remove him from office,” Johnson added. “It is entirely possible that Vindman fits this profile.”

The lawmaker added that his view is reinforced by Vindman’s own words from his previous closed-door testimony.

“Vindman’s testimony, together with other witnesses’ use of similar terms such as ‘our policy,’ ‘stated policy,’ and ‘long-standing policy’ lend further credence to the point I’m making,” Johnson wrote.

“Whether you agree with President Trump or not, it should be acknowledged that the Constitution vests the power of conducting foreign policy with the duly elected president. American foreign policy is what the president determines it to be, not what the ‘consensus’ of unelected foreign policy bureaucrats wants it to be,” he continued.

Johnson recommended that individuals who disagree with Trump have a choice on their course of action.

“If any bureaucrats disagree with the president, they should use their powers of persuasion within their legal chain of command to get the president to agree with their viewpoint,” Johnson wrote. ” In the end, if they are unable to carry out the policy of the president, they should resign. They should not seek to undermine the policy by leaking to people outside their chain of command.”