This post has been updated:

A group of House Republicans led by the chairman of a powerful committee moved Tuesday to impeach the head of the Internal Revenue Service, saying he violated the public trust and lied to Congress as it investigated the treatment of conservative groups.

The announcement by Rep. Jason Chaffetz (R-Utah), chairman of the House Oversight and Government Reform panel, came four days after the Justice Department formally closed its investigation of the targeting scandal without filing criminal charges.

The last-ditch effort to remove IRS Commissioner John Koskinen follows through on a threat Chaffetz made over the summer after he called on President Obama to fire the commissioner, whom he accused of erasing back-up tapes containing thousands of e-mails written by Lois Lerner, the central IRS official in the scandal.

Koskinen took over the agency in late 2013 after the scandal broke. But Chaffetz said Koskinen had told lawmakers his agency had turned over all e-mails that were relevant to the investigation, and when e-mails were found to be missing, said they were unrecoverable.

“These statements were false,” Chaffetz said in a statement Tuesday.

“Commissioner Koskinen violated the public trust,” Chaffetz said. “He failed to comply with a congressionally issued subpoena, documents were destroyed on his watch, and the public was consistently misled.”

“Impeachment is the appropriate tool to restore public confidence in the IRS and to protect the institutional interests of Congress.”

A statement issued Wednesday morning by the IRS says the agency ”vigorously disputes” the allegations.

”We have fully cooperated with all of the investigations,” the IRS said.

The oversight committee has been investigating the IRS for more than two years, since agents were discovered to have subjected conservative groups applying for tax-exempt status to additional scrutiny.

Chaffetz was joined by 18 committee Republicans in sponsoring an impeachment resolution, which now goes to the House Judiciary Committee.

House Democrats quickly denounced the move as political grandstanding.

“Calling this resolution a ‘stunt’ or a ‘joke’ would be insulting to stunts and jokes,” Rep. Elijah E. Cummings (Md.) the committee’s top Democrat, said in a statement. He said the impeachment resolution was “ridiculous” and a waste of taxpayer money.

“Instead of squandering millions of taxpayer dollars on baseless partisan attacks,” Cumming said, “the committee should focus on issues that matter to all Americans, like bringing down the costs of prescription drugs, as I have requested for the past year with no success.”

Cummings added that there is no evidence Koskinen did what Chaffetz is accusing him of and said IRS has spent $20 million and 160,000 employee hours cooperating with investigations.

Pursuing impeachment against an agency leader is highly unusual, and a step beyond contempt charges, the mechanism House Republicans tried to use against both Lerner and former attorney general Eric H. Holder Jr. in past disputes.

More than a century ago, Congress brought articles of impeachment against War Secretary William Belknap in 1876, after the House of Representatives uncovered evidence supporting a pattern of corruption.

He resigned during the proceedings.