Michael Cohen, the longtime personal attorney of U.S. President Donald Trump, goes before the Senate intelligence committee Tuesday for the first of three days of congressional testimony.

Committee Chairman Richard Burr says there will be no question that is off limits, though the answers Cohen gives will be private due to the closed-door nature of Tuesday’s session.

The same will be true Thursday when Cohen testifies before the House intelligence committee. Both committees are expected to ask Cohen about any ties between Trump’s 2016 election campaign and Russia.

Wednesday’s session will be different, with his appearance before the House Oversight Committee open to the public and limited to questions about Trump’s finances, including his company’s dealings, potential business conflicts of interest and hush money paid to two women who said they had sexual affairs with Trump.

Cohen has been sentenced to serve three years in prison after being convicted of lying to Congress in previous appearances, campaign finance violations tied to the hush money payments, bank fraud and tax evasion.

His close ties to Trump over the course of more than 10 years make Cohen a particularly interesting witness to lawmakers, as well as special counsel Robert Mueller, who is investigating Russian election interference and potential links to Trump’s campaign.