House Oversight Committee Chairman Darrell Issa is facing a battle in Congress to pass bipartisan legislation to overhaul the U.S. Postal Service, including an end to Saturday delivery.

The agency has lost billions of dollars in the past decade due to the impact of the Internet, and it’s even been forced to default on three $5.5 billion payments into a healthcare fund for future retirees, according to The Washington Post.

Issa, whose tenure as committee chairman is winding down due to term limits, is pushing for sweeping changes to the USPS, and he has the support of his panel’s Senate counterpart, the Homeland Security and Governmental Affairs Committee, led by Sen. Thomas Carper, a Delaware Democrat.

The two committees have introduced a series of measures in recent months, which would have allowed the postal service to slash costs and create new products making it more competitive, while also restructuring its debt to make the payments for future retirees.

But the proposals to finally end the three-year effort to stabilize the postal service were knocked back. The Post cited sources saying that a Democrat-led Senate and the Republican-led House are unlikely to pass a USPS bill before the midterm elections in November.