WASHINGTON (Reuters) - The top Republican on a U.S. House of Representatives oversight committee that is investigating President Donald Trump blasted the Democratic-led probe on Thursday as a “draconian inquisition” and an abuse of congressional power.

FILE PHOTO: U.S. Representative Doug Collins addresses the media during the 2017 "Congress of Tomorrow" Joint Republican Issues Conference in Philadelphia, Pennsylvania, U.S. January 25, 2017. REUTERS/Mark Makela

The House Judiciary Committee’s ranking Republican, Doug Collins, said the panel’s investigation into obstruction of justice, corruption and abuse of power under Trump surpasses the scope of legitimate legislative inquiry and violates the U.S. Constitution.

Judiciary Committee Chairman Jerrold Nadler launched the investigation on Monday by sending document requests to 81 government agencies, business entities and individuals associated with Trump, including his adult sons, Donald Trump Jr. and Eric Trump.

“Your requests are part of a concerted effort to target and punish associates of the president,” Collins wrote to Nadler in a March 7 letter released by the Republican’s office.

“This effort to intimidate those who choose to associate with the president ‘through actual or threatened imposition of government power or sanction’ violates the First Amendment.”

Nadler’s office was not immediately available to comment on the letter, which cited several court cases as legal precedents for limiting the scope of congressional investigations.

Democrats, who won control of the House last year in an election marked by voter opposition to Trump, say they must investigate the Republican president to uphold the rule of law after two years of inactivity under the previous Republican majority.

The committee is seeking evidence of misconduct by Trump, including any effort to obstruct U.S. Special Counsel Robert Mueller’s probe of Russian election meddling during the 1996 presidential election and any collusion between Moscow and the Trump campaign, and other federal investigations.

But Collins, a Georgia Republican, said Democrats could instead upend the rule of law: “Your 81 letters appear to be little more than a deep-sea fishing expedition with the purpose of exposing private matters and airing alleged dirty laundry rather than legislating.”

While some Democrats want to impeach Trump, Nadler and other House Democratic committee chairmen say they are far from any such decision.

But without impeachment proceedings providing a legislative purpose, Collins said the House Judiciary probe threatens to usurp the law enforcement powers granted to the executive and judicial branches of government by the Constitution, while burdening innocent individuals with unnecessary legal costs.

“It is my hope that your draconian inquisitions are not returning this committee to the dark days of 16th-century England,” he said.

Russia has denied meddling in the 2016 election. Trump has said there was no collusion between his campaign and Moscow, and has labeled the Mueller investigation a “witch hunt.”