A planned AFL-CIO rally for today to defend Saturday mail delivery may have been a bit premature after the  Government Accountability Office is claiming that the USPS cannot, by law, cut mail delivery to fewer than 6 days.

Bloomberg News reports:

The service is bound by law to deliver mail six days a week, and is incorrect in interpreting that a temporary measure used to fund U.S. government operations released it from that requirement, the GAO said in a letter to Representative Gerald Connolly, a Virginia Democrat, who requested that the watchdog agency look at the matter.
The plan to cut delivery of letter mail while retaining package delivery on Saturdays “rests upon a faulty USPS premise,” GAO General Counsel Susan Poling said in the letter.
The GAO’s conclusion sparked different interpretations from parties that support and oppose ending Saturday mail delivery. The labor union whose employees would be most affected said it doesn’t expect the dispute to end in a courtroom.

But some Republicans, including Representatives Issa and Coburn, are fighting this interpretation, saying that because package deliveries will continue on Saturdays, mail service is not technically being cut.

When it comes to cutting budgets, expect this fight over and over.