Sen. Sherrod Brown, D-Ohio, joined 23 other senators in urging the U.S. Postal Service to “reconsider” its decision to end Saturday mail delivery, a move the postal service said is necessary to save $2 billion annually at a time when annual losses are nearly $16 billion.

In a letter to Postmaster General Patrick Donahoe, the 23 Senate Democrats and Independent Bernie Sanders contended that reducing mail delivery to just five days a week would cost thousands of jobs and “will hurt middle class families.” In addition, the lawmakers argued that the Postal Service would be violating the law by going from six days to five days.

“We urge you to reconsider your decision and not take this action unless authorized by Congress,” the senators wrote.