Former President Bill Clinton and former Secretary of State Hillary Clinton said Tuesday they will not comply with a congressional subpoena seeking their testimony in a House committee investigation into Jeffrey Epstein.

The Clintons, in a letter released on social media, slammed the House Oversight probe as "legally invalid” even as Republican lawmakers prepared contempt of Congress proceedings against them. The Clintons wrote that the chair of the House Oversight Committee, Republican Rep. James Comer, is on the cusp of a process "literally designed to result in our imprisonment.”

"We will forcefully defend ourselves,” wrote the Clintons, who are Democrats. They accused Comer of allowing other former officials to provide written statements about Epstein to the committee, while selectively enforcing subpoenas against them.

Comer said he’ll begin contempt of Congress proceedings next week. It potentially starts a complicated and politically messy process that Congress has rarely reached for and could result in prosecution from the Justice Department.

"No one’s accusing the Clintons of any wrongdoing. We just have questions," Comer told reporters after Bill Clinton did not show up for a scheduled deposition at House offices Tuesday.