Rep. Devin Nunes (R-Calif.) tried using part of his time while questioning National Security Council official Lt. Col. Alexander Vindman during Tuesday mornings impeachment hearing to gather information about the whistleblower but was quickly shut down by House Intelligence Committee Chairman Adam Schiff.

Republicans defending President Donald Trump have attempted to create suspicion around the whistleblower report about a July 25 phone call between the U.S. president and his Ukrainian counterpart that kicked off the inquiry.

Beginning his line of questioning, Nunes asked Vindman whether he had spoken about the phone call to anyone outside the White House.

Vindman said that he had because it is part of his job. He provided a readout of the call to two cleared U.S. government officials with the appropriate need to know about Trumps conversation with Ukrainian President Volodymyr Zelensky, he testified. One of them was a State Department official, and the other was the individual in the intelligence community thought to be the whistleblower.

Nunes seized on the opportunity to press Vindman for more details about the whistleblower, demanding to know the specific agency to which he or she belongs before Schiff intervened.

Please stop, Schiff said. I want to make sure that there is no effort to out the whistleblower through these proceedings.

Vindman then clarified that he did not know the identity of the whistleblower, merely that the individual had the security clearance necessary to receive information about the call.

His response appeared to perplex Nunes, who told the witness he could either answer the question or you can plead the Fifth.

At that point, Vindmans counsel stepped in, telling Nunes that were following the rule of the committee, the rule of the chair with regard to this issue.

This does not call for an answer that is invoking the Fifth or anything like that, the counselor told the ranking member.

Schiff later intervened again during questions from Rep. Jim Jordan (R-Ohio) about the whistleblowers identity.

You have said even though no one believes you, you have said you dont know who the whistleblower is, Jordan retorted to Schiff. So how is this outing the whistleblower?

As the impeachment inquiry has marched on, the whistleblowers legal team has said they have received numerous death threats .

But Republicans have continued to push for the whistleblowers unmasking even after current and former government officials have corroborated details of the report during public and private hearings, including several firsthand accounts.