CNN  — 

Rudy Giuliani told CNN on Friday that he would not testify for the House of Representatives’ impeachment inquiry without consulting his client, President Donald Trump.

Trump’s personal lawyer said his work for the President should be protected by attorney-client privilege.

“Ultimately, if I were to say yes and he were to say no, I can’t testify,” Giuliani said, adding that he has not talked to Trump about the possibility he would testify.

The former New York City mayor has become a central figure in the unfolding scandal surrounding Trump’s communications with Ukrainian President Volodymyr Zelensky that have led to a House impeachment inquiry into the President’s conduct. According to a White House-released transcript of a July call between the two leaders, Trump asked Zelensky to work with Giuliani and Attorney General William Barr to investigate former Vice President Joe Biden and his son, Hunter, though there is no evidence of wrongdoing by either Joe or Hunter Biden.

Giuliani said he has not heard from any of the three House committees investigating whether Trump acted improperly in his communications with the Ukrainians. Asked if he was concerned he would be subpoenaed by the House, Giuliani laughed.

“I consider them a joke. A sad joke. They have no legitimacy. I would think of challenging their subpoena on the grounds that they’re not a legitimate committee,” Giuliani said.

Giuliani and Barr are among those who House Democrats have told CNN they would like to hear from. On Friday, Rep. Mike Quigley, a Democratic member of the House Intelligence Committee, told CNN’s Jim Sciutto that he has “several questions” for Giuliani, including whether the President’s personal lawyer has a security clearance.

“Rudy may be the best source of information, because he doesn’t know what he shouldn’t say,” Quigley said, adding that he thinks Barr is “part of that list” of officials the committee will call to testify.

Later Friday, Giuliani told CNN that he was no longer planning to attend an event in Armenia next Tuesday after The Washington Post reported that Russian President Vladimir Putin would be in attendance as a guest.

In its report, the Post said Giuliani’s appearance at the event would be paid and that the event was backed by the Kremlin. The post, citing the event’s agenda, said the former mayor was going to take part in a panel “led by Sergey Glazyev, a longtime Putin adviser who has been under U.S. sanctions since Russia’s invasion of Ukraine five years ago.”

This story has been updated

CNN’s Dana Bash contributed to this report.