The Postal Service violated the Hatch Act when it let USPS employees work for a union-funded push to elect Hillary Clinton and other Democrats while on unpaid leave from the agency, according to a new report by the Office of Special Counsel.

The report, first obtained by Fox News, was issued after a complaint from Sen. Ron Johnson (R-WI), the Chairman of the Senate Committee on Homeland Security and Governmental Affairs, when concerns were passed on to him by a USPS employee.

The employee told Johnson that he was concerned that the USPS “incurred unnecessary overtime costs and improperly coordinated with the National Association of Letter Carriers (NALC) when it released NALC members for several weeks of ‘union official’ leave without pay to participate in the AFL-CIO’s Labor 2016 program.”

That program tried to “elect Hillary Clinton and pro-worker candidates across the country” via canvassing, phone banks, and other such efforts. The report found that 97 members of NALC, which endorsed Clinton for the presidency, requested the leave without pay to participate in the pro-Democrat activities.

The NALC targeted battleground states, both in terms of the presidency, but also for Senate races.

“There is a lot [at] stake on Tuesday, Nov. 8 — for our country, our job, and our families. Starting in the key battleground states of Pennsylvania, Ohio, Florida, Wisconsin, and Nevada, NALC and America’s letter carriers are ready to unite behind Hillary Clinton to make this great country even greater,” the NALC said in a June press release.

The investigation found that the post office systematically violated the Hatch Act — which prevents federal employees from engaging in certain political activities. The report said in particular that the “practice of facilitating carrier releases for the union’s political activity resulted in an institutional bias in favor of NALC’s endorsed political candidates, which the Hatch Act prohibits.”

The report also found that staff in branches were released for the AFL-CIO campaign despite their manager’s objections that it would leave them understaffed.

“Explain to me why we are releasing people for 30 days,” said one Wisconsin manager in an email to a supervisor.

“[W]e have to release,” came the response.

However, the report concluded that the USPS did not look to help Democrats and that its bias was unintentional, with the intention instead being to curry favor with the AFL-CIO. As a result, the Office announced that it would not seek disciplinary action, but did call for “agency-wide corrective action.”

Adam Shaw is a Breitbart News politics reporter based in New York. Follow Adam on Twitter:  @AdamShawNY