Rudy Giuliani said he is considering legal action against House Democrats, who have subpoenaed him for documents related to the whistleblower complaint against his client President Trump about a July phone call he had with the Ukrainian President Volodymyr Zelensky.

The former New York City mayor revealed his idea for combating the Democrats in their impeachment inquiry during an interview Tuesday on Fox News.

"I had a couple of talks with civil rights lawyers and a constitutional lawyer today, and here’s what they are recommending. That we should bring a lawsuit on behalf of the president and several of the people in the administration, maybe even myself as a lawyer, against the members of Congress, individually, for violating constitutional rights, violating civil rights," he told host Laura Ingraham.

Giuliani accused Democratic lawmakers of doing "extraordinary things," including interfering with the president's ability to adhere to Article II, Section 3 of the Constitution to ensure "laws be faithfully executed."

In talking with Giuliani, Ingraham struck a note of caution. "We are in uncharted territory, she said while also calling her guest's idea a potential "legal tactic."

House Speaker Nancy Pelosi initiated a formal impeachment inquiry last week after the president admitted to discussing former Vice President Joe Biden with Ukrainian President Volodymyr Zelensky. A whistleblower complaint from an intelligence official has raised concerns that Trump may have leveraged millions of dollars in security aid to convince Zelensky to assist Giuliani to investigate Biden and his son Hunter, though Trump and his allies insist there was no "quid pro quo."

Among the Democrats Giuliani said he would sue in a civil case will be House Intelligence Committee Chairman Adam Schiff.

"We have to raise their violation of constitutional civil rights. This is worse than McCarthy," he said, referring to former Sen. Joe McCarthy's Red Scare of the 1950s.