Giuliani associate says John Bolton is a key impeachment witness, bolstering Democrats' calls for him to testify in Senate trial

• Rudy Giuliani's associate Lev Parnas told MSNBC's Rachel Maddow on Wednesday that former national security adviser John Bolton knows "100%" about the Trump administration's efforts to pressure Ukraine.
• "He has a lot to say," Parnas told Maddow.
• Democrats in both the House and Senate have called for Bolton to testify in the impeachment proceedings.
• Bolton released a statement on January 6 saying he was "prepared to testify" if subpoenaed by the Senate during the impeachment trial.
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Rudy Giuliani's associate Lev Parnas said on Wednesday that former national security adviser John Bolton is a "key witness" to President Donald Trump's dealings with Ukraine.

In an exclusive interview with MSNBC's Rachel Maddow on Wednesday, Parnas discussed his role in Trump's apparent pressure campaign against Ukraine, which is at the center of Trump's impeachment.

Parnas and Trump's personal lawyer Giuliani played important roles in Trump's alleged efforts to prod Ukrainian President Volodymyr Zelensky into publicly committing to investigations that would benefit Trump politically.

Parnas told Maddow that Bolton is a "key witness" to the events that played out in Ukraine.

"He has a lot to say," Parnas claimed. "He's a key witness to his conversation to Zelensky and why he left or got fired."

Parnas also asserted that Bolton was "in the loop" on Trump's plans.

"But you believe he knows what the administration was pressuring Ukraine to do?" Maddow asked.

"Bolton? 100%. He knows what happened there," he responded.

Parnas pleaded not guilty to charges of campaign-finance violations last year.

House Democrats have called for Bolton to testify in the impeachment inquiry and now Senate Democrats are urging him to testify during proceedings. Bolton did not appear for a closed-door deposition in November, but on January 6 he released a statement saying he was "prepared to testify" if subpoenaed by the Senate.

After a New York Times report said that Bolton, Secretary of State Mike Pompeo and Defense Secretary Mark Esper were in a meeting with Trump begging him to release military aid to Ukraine, Senate Minority Leader Chuck Schumer said that having Bolton and other top officials testify would be a "game changer."

"This new story shows all four witnesses we Senate Democrats have requested - Mick Mulvaney, John Bolton, Michael Duffey, and Robert Blair - were intimately involved and had direct knowledge of President Trump's decision to cut off aid in order to benefit himself," Schumer said in a statement.

But Trump has signaled that he would try and block Bolton's impeachment testimony. In an interview with Fox News, Trump said he had "no problem" with Bolton testifying, but added that he was worried about the impact such a testimony would have on "future presidents" and issues of national security.

"There are things that you can't do from the standpoint of executive privilege," he said. "Especially, a national security adviser ... You can't have him explaining all of your statements about national security concerning Russia, China, and North Korea - everything. We just can't do that."

On Wednesday, the House voted to transmit the articles of impeachment to the Senate. The trial is expected to begin next week; it is unclear if witnesses will be called.

Sonam Sheth contributed to this report.