Congress has a message for Mark Zuckerberg: You’re the one that we want.

Members of the House and Senate formally asked the Facebook chief executive to come to Capitol Hill to explain how 50 million users’ data got into the hands of political consultancy firm Cambridge Analytica.

“Mr. Zuckerberg has stated that he would be willing to testify if he is the right person,” House Energy and Commerce Committee Chairman Greg Walden and ranking Democratic member Frank Pallone, Jr. said in a Friday statement. “We believe, as CEO of Facebook, he is the right witness to provide answers to the American people.”

In a CNN interview on Wednesday, Zuckerberg said he was not unwilling to make the trip to Washington.

“The short answer is, I’m happy to if it’s the right thing to do,” he said, before hedging a bit: “What we try to do is send the person at Facebook who will have the most knowledge. If that’s me, then I am happy to go.”

The House Energy and Commerce Committee did not say when it planned the hearing, but it will not happen until Congress returns from a two-week recess.

A Facebook spokesman confirmed the company had received the House letter and was reviewing it, but did not say whether or not Zuckerberg would agree to testify.

Separately, the leaders of the US Senate Commerce Committee also asked Zuckerberg to testify. Senator John Thune, the committee chairman, and Bill Nelson, the top Democrat, said the committee would work with Facebook “to find a suitable date for Mr. Zuckerberg to testify in the coming weeks.”

Facebook shares continued their downward spiral Friday, closing down 3.3 percent at $159.39.