Postal workers worried that eliminating Saturday delivery could imperil the U.S. mail service will hold a demonstration downtown this afternoon at lunchtime.

Local members of the American Postal Workers Union, joined by area labor leaders, will hold an informational picket outside of the post office on Market Street to protest the post office's plan to move to a five-day delivery.

According to the union, ending Saturday delivery would lead to further cuts that could "initiate a 'death spiral' for the nation's mail system."

In March, the Post Office issued a report that says ending Saturday delivery -- the lightest day for letter carriers -- could save the cash-strapped delivery service $3 billion a year.

The report says that 44 percent of the postal work service is eligible for retirement between now and 2014, potentially easing the need for layoffs, which would obviously be a key concern for the unions.

Key corporate customers -- including Time Warner and NetFlix -- have already endorsed eliminating Saturday delivery.

More interest to readers of this blog though might be what effect ending Saturday mail could have on campaign season, where timing is key to getting literature to targeted voters.