WASHINGTON -- A group of U.S. Postal Service employees and supporters launched a hunger strike Monday on Capitol Hill, urging action from lawmakers in order to save an agency they said was imperiled by Congress itself.

The postal workers and boosters said they were trying to draw attention to a wonky yet crucial element of postal service reform being considered: the repeal of what's called the "prefunding mandate," a 2006 requirement from Congress that the USPS prefund the retiree health benefits for its workers 75 years in advance, to the tune of about $5.5 billion per year.

"Congress created the problem, Congress can fix it," said Jamie Partridge, a retired letter carrier who worked in Portland, Ore., for 27 years and is taking part in the hunger strike. "We're just frustrated. We're indignant, we're outraged, we're here to shame Congress into doing the right thing. We're willing to suffer, to go on a hunger strike in order to show our indignation."

Although the volume of first-class mail has declined, the prefunding mandate has accounted for most of the red ink recently incurred by the postal service. Postal unions and many workers have said that the mandate is the primary threat to the agency's financial stability, while the agency's postmaster general, Patrick Donahoe, has insisted that eliminating the mandate is no silver bullet in a digital age of falling mail volume.

Along with many members of Congress, Donahoe has called for the elimination of Saturday delivery, the shedding of workers now covered by no-layoff clauses and the closing of some postal facilities -- measures generally opposed by USPS employees. Unions and workers have said that drastic cuts to service will create a "death spiral" in which a diminished service leads inevitably to more and more cuts.

The workers who launched the hunger strike on Monday had the backing of Rep. Dennis Kucinich (D-Ohio), who stood with them on the Capitol Grounds as they announced their four-day strike. Kucinich said the agency was in danger of being privatized.

"I'll continue to fight any efforts to weaken the postal service and any efforts to privatize essential services," said Kucinich, who, now near the end of eight terms in Congress, lost his primary to fellow Democrat Rep. Marcy Kaptur (D-Ohio) earlier this year after redistricting. "Make no mistake about it: There is an effort to try to privatize even more postal services. This would inevitably result in less service and higher costs for postal services for the American people."

A wide array of interest groups hold a stake in postal service reform -- including a roughly $1 trillion mailing industry -- each with its own prescription for what needs to be done. Several pieces of legislation have been introduced in Congress, although only the Senate has passed a comprehensive reform bill. The House is expected to take up the issue after the July 4 holiday recess.

The roughly 10 hunger strikers wore t-shirts that said "Save the Eagle from Starvation" -- the eagle being the agency's symbol -- and said they planned on going without food through Thursday. Tom Dodge, a postal service truck driver from Baltimore, Md., told HuffPost that he was taking part in the strike because he felt the cuts being floated threatened to undermine the concept of universal delivery that's at the core of the agency's mission.

"I think it’s a basic right for every citizen to have cheap, reliable mail service," Dodge said.

Kucinich urged the hunger strikers to look after their health.

"Please be careful," he said. "Have enough water. Temperatures are hot here in Washington. Make sure you check with your doctor, and don't hurt yourself. But the moral position you have here today ... you feel so strongly about protecting the postal service you're ready to put your health on the line. ... That tells you something about the men and women who serve here."

Asked if he considered joining the hunger strike himself as a show of solidarity, Kucinich said, "I'm a vegan. I'm kind of hungry all the time."