Washington (CNN) The top Republicans on the committees involved in the impeachment inquiry on Wednesday demanded House Intelligence Committee Chairman Adam Schiff bring the whistleblower who filed a complaint about President Donald Trump and Ukraine in for public testimony.

"We are surprised by your announcement that the Committees will not receive testimony from the anonymous intelligence community employee whose complaint initiated the so-called impeachment inquiry," wrote Reps. Jim Jordan of the House Oversight Committee, Devin Nunes of the House Intelligence Committee, and Michael McCaul of the Foreign Affairs Committee in a letter.

"You had earlier committed that the employee would provide 'unfiltered' testimony 'very soon' only to reverse course following revelations that the employee had a bias against President Donald Trump and that you had received a secret, early account of the allegations. As the so-called impeachment inquiry gathers information that contradicts the employee's allegations, we ask that you arrange for the Committees to receive public testimony from the employee and all individuals he or she relied upon in formulating the complaint."

The letter comes as the Democratic-led impeachment inquiry into the President continues to escalate with depositions of key witnesses in the investigation happening behind closed doors.

Democrats have said they will not bring the whistleblower in for public testimony given concerns about keeping the person's identity secret. Attorneys for the whistleblower have said their client's security is a priority as the President has said he wanted to know the whistleblower's identity and has tried to discredit the individual.