The U.S. Postal Service is often the butt of jokes, but there's nothing funny about the agency's bottom line.

The USPS is losing up to $25 million dollars a day. Until now, taxpayers have not been on the hook for its mounting losses, but that could be about to change. A bailout recently approved by the Senate would appropriate $34 billion in federal money.

TAXPAYER CALCULATOR: Postal Service overhaul

"If the post office was a business, it would be in bankruptcy," said Rep. Dennis Ross, R-Fla. "It's insolvent."

Ironically, however, Congress shares much of the blame. For years, the Postal Service begged Washington for the freedom to cut its own budget by closing post offices and cutting employees. But Congress, under pressure from rural constituents and labor unions, prevented the cuts, and the service continued to bleed red ink.

In December, the USPS said it wanted to close more than half of its mail processing centers, eliminate 28,000 jobs, end overnight delivery of first-class mail, close 3,700 local post offices and end Saturday delivery.

The Senate said no, prohibiting the Postmaster General from taking those actions altogether, or delaying them for two to three years.

A bipartisan group of Senators led by Joe Lieberman, I-Conn., and Susan Collins, R-Maine, said it was a "compassionate" way to reform the service, using buyouts and incentives to reduce the workforce.

Postmaster General Patrick Donahoe objected, claiming the Senate is stopping him from saving $20 billion. House Republicans call the Senate bill a joke, a special-interest spending binge that does nothing to reform an agency losing business every day, as more and more Americans use e-mail and electronic banking.

"Over the last six years, the Postal Service lost 25 percent of their revenues," Ross said. "We as a Congress have to look at the fact that the post office is not in the 21st century. It's still 50 years behind and we have to bring it up, modernize it and allow it to take advantage of market trends."

A competing House bill co-sponsored by Ross allows the postmaster to cut services, close offices, raise fees and force existing postal employees to pay for their own retirement. The bill faces some Democratic opposition and has yet to reach the House floor for a vote.

Unless the House and Senate compromise, the USPS could announce post office closings next week.