A recently revealed federal investigation into Postmaster General Louis DeJoy’s political fundraising could derail the Postal Service Reform Act, a crucial bipartisan bill meant to provide much-needed relief to the U.S. Post Office.

The Washington Post reports that a spokesperson for DeJoy confirmed the postal chief is cooperating with the probe, which is linked to fundraising at his now-defunct North Carolina business. Current and former employees of DeJoy and New Breed Logistics have been interviewed by FBI agents in the past few weeks about allegations that employees were encouraged to donate to Republican candidates and were later reimbursed with employee bonuses. Through his spokesperson, DeJoy denies all wrongdoing.

The investigation and potential legal trouble for DeJoy jeopardizes his attempts to institute one of the biggest overhauls in the history of the USPS, which must have bipartisan support to happen. There are bills advancing in Congress that would restructure the Postal Service’s finances and ease $44 billion of debt, as well as finally address the controversial $5 billion annual retiree health-care payments the agency must pay.

But as one source told the Post, the investigation into DeJoy jeopardizes the bill simply because some people in Congress aren’t very invested in making it work. “Aside from the [postmaster general] being under investigation, nobody ultimately wants to do anything [on the bill] because everyone’s selfish and unreasonable,” a Senate aide said anonymously.

Some House Democrats have already privately discussed dropping their support for the measure in light of the DeJoy investigation, according to the Washington Post’s reporting. As of now, DeJoy still has the support of the agency’s board of governors. The six-member panel has resisted previous calls to remove DeJoy, who is widely unpopular with Democrats and their supporters, because they believe he tried to undermine the effectiveness of the USPS and caused massive slowdowns in mail service.