IRS chief to Congress: I never wanted this job

The head of the Internal Revenue Service never asked to lead the agency, he said in written testimony on Tuesday, adding that he had been "happily retired" and that the move to impeach him was "wholly improper."

"I have great respect for our institutions of government," IRS Commissioner John Koskinen said in the statement to the House Judiciary Committee, a hearing he declined to attend. "When I began my services as commissioner ... I took over an agency under investigation by six different bodies and buffeted by ongoing, serious controversy. I regret that, in the period since then, we have not been able to bring these matters to a conclusion."

Koskinen took the helm of the agency in December 2013 after his predecessor, Lois Lerner, was forced to resign amid revelations that the agency had improperly targeted conservative nonprofits for auditing.

However, Koskinen has drawn the ire of members who suggest he has obstructed their investigation into Lerner's practices since he took over. He also faced criticism for failing to defend the agency against cyberattacks, and for failing to verify Social Security numbers for fear of outing illegal immigrants.

"I never sought the position of IRS commissioner," Koskinen wrote in his own defense. "I was happily retired. I served on the boards of two large, publicly-traded companies and tried to keep up with my grandchildren. But I agreed to serve when approached by the current administration in May 2013, because I have a longstanding commitment to public service, and because I understand the importance of the IRS to the government and the nation.