The committee issued subpoenas to Giuliani and other members of former president Donald Trump’s legal team last month.

Giuliani, the 76-year-old former New York City mayor, helped lead Trump’s failed effort to overturn the result of the 2020 election and cling to power.

But while several Trump allies have refused to co-operate with the committee, The New York Times reported on Saturday that Giuliani is in discussions with the panel about responding to its questions.

The extent of Giuliani’s co-operation with the committee remains unclear.

But the subpoena sought all documents and a deposition that Giuliani had about the campaign that he and other Trump allies embarked upon in the months after the 2020 election.

Here, Newsweek rounds up five crucial questions the panel could ask Giuliani about what he saw and did in the days leading up to and including January 6, 2021.

An attorney representing Giuliani has been contacted for comment.

1. What Did ‘Trial by Combat’ Mean?

Giuliani was a chief proponent of Trump’s baseless claims of widespread voter fraud in the 2020 election.

The panel will likely question Giuliani about remarks he made at a rally in front of the White House before the riot at the Capitol, where he pushed those false claims and used rhetoric that alluded to violence.

“Let’s have trial by combat,” Giuliani said. “I’m willing to stake my reputation, the President is willing to stake his reputation, on the fact that we’re going to find criminality there.”

2. Was There a Plan for Fake State Electors?

The committee will also likely want to know about Giuliani’s role in a reported scheme to use fake slates of electors to keep Trump in office.

It allegedly involved persuading lawmakers in contested states to draw up alternate slates of electors showing Trump triumphant in states actually won by Joe Biden.

Thompson’s letter said Giuliani had “actively promoted claims of election fraud on behalf of former president Trump and sought to convince state legislators to take steps to overturn the election results.”

3. What About Seizing Voting Machines?

The committee will undoubtedly want to ask Giuliani about a plan to use the Department of Homeland Security to seize voting machines.

The letter from Thompson cited witness testimony and public reporting that Giuliani had urged Trump “to direct the seizure of voting machines around the country after being told that the Department of Homeland Security had no lawful authority to do so.”

4. Can You Explain This Jan. 6 Voicemail?

Giuliani may also face questions about a voicemail he left hours after the riot at the Capitol began, but before Congress restarted the session to certify Biden’s electoral victory.

Giuliani called Sen. Mike Lee, but left a message for Sen. Tommy Tuberville.

“Senator Tuberville—or should I say Coach Tuberville, this is Rudy Giuliani, the President’s lawyer,” Giuliani said in the message. “I’m calling you because I want to discuss with you how they’re trying to rush this hearing and how we need you, our Republican friends, to try to just slow it down.”

5. What Contact Did You Have with Trump on Jan.6?

The panel will want to know the details of contact Giuliani had with Trump and members of Congress in the days leading up to January 6.

It is referenced in the subpoena letter Rep. Bennie Thompson, Democratic chairman of the panel, sent to Giuliani.

“According to public reporting, on January 6 and in the days prior, you were in contact with then-President Trump and Members of Congress regarding strategies for delaying or overturning the results of the 2020 election,” Thompson wrote.