Former independent counsel Kenneth Starr and Harvard Law professor emeritus Alan Dershowitz have joined President Donald Trump’s impeachment legal team ahead of the Senate’s upcoming trial.

“Professor Dershowitz will present oral arguments at the Senate trial to address the constitutional arguments against impeachment and removal,” a spokesperson for the legal team said in a statement Friday. “While Professor Dershowitz is non-partisan when it comes to the constitution—he opposed the impeachment of President Bill Clinton and voted for Hillary Clinton— he believes the issues at stake go to the heart of our enduring Constitution.”

Dershowitz, one of the country’s most high-profile constitutional lawyers, confirmed the news to CNBC. “The president asked me to do this, and the legal team asked me to do this,” he said.

Starr, a former appeals court judge who headed up the investigation into the Whitewater the Monica Lewinsky scandals, has yet to confirm the news.

Robert Ray, an ex-federal prosecutor and independent counsel who took over for Starr in the Whitewater probe, is also expected to join the president’s legal team, CNN reports.

“You can confirm that I expect an announcement this afternoon,” Ray told CNBC of the report.

White House Counsel Pat Cipollone and Jay Sekulow, President Trump’s personal attorney, will lead the defense team.

The development comes after House Speaker Nancy Pelosi (D-CA) bowed to pressure on Wednesday from Republicans and several Democrats to transfer two articles of impeachment — abuse of power and obstruction of Congress — to the Senate after a near four-week delay. Additionally, Pelosi announced the seven House Democrats who will serve as impeachment managers in the trial, naming: House Intelligence Committee Chairman Rep. Adam Schiff (D-CA), House Judiciary Committee Chairman Rep. Jerry Nadler (D-NY), and Reps. Hakeem Jeffries (D-NY), Val Demings (D-FL), Zoe Lofgren (D-CA), Jason Crow (D-CO), and Sylvia Garcia (D-TX). Schiff was appointed lead impeachment manager.

Senate Majority Leader Mitch McConnell (R-KY) said this week that the trial will likely start next Tuesday.

“We’ll be able to go through some preliminary steps here this week, which could well include the Chief Justice coming over and swearing-in members of the Senate and some other kind of housekeeping measures…which would set us up to begin the actual trial next Tuesday,” McConnell confirmed at a Capitol Hill press conference.

President Trump has repeatedly criticized the Democrats’ impeachment effort as a “hoax” and an “illegal, partisan attempted coup.”