Nearly every Senate Republican signed a letter sent to Senate Majority Leader Chuck Schumer on Tuesday asking him to continue enforcing the Senate's previous, more formal unwritten dress code.

Axios reported earlier this week that Schumer recently asked the Senate sergeant-at-arms to no longer enforce the dress code on the chamber floor. The move was seen as reflective, at least in part, of Pennsylvania Democratic Sen. John Fetterman's preference for wearing shorts and a hoodie.

"The Senate is a place of honor and tradition, and the Senate floor is where we conduct the business of the American people. It is where we debate the policies which impact every American family and, when necessary, it is where we must make the gravest decision imaginable -- whether to send our fellow Americans into battle to defend the freedoms we all hold dear. The world watches us on that floor and we must protect the sanctity of that place at all costs," the senators wrote.

"Allowing casual clothing on the Senate floor disrespects the institution we serve and the American families we represent. We, the undersigned members of the United States Senate, write to express our supreme disappointment and resolute disapproval of your recent decision to abandon the Senate's longstanding dress code for members, and urge you to immediately reverse this misguided action."

The letter was signed by every member of the Republican Senate caucus except Katie Boyd Britt of Alabama, Mike Braun of Indiana and Josh Hawley of Missouri. CNN has reached out to their offices for comment.

Schumer's move follows a larger national trend toward more casual clothing in the workforce. Occasionally in recent years, some objections have been raised over Congress' formalities, and in 2017, then-House Speaker Paul Ryan relaxed rules on attire after dozens of congresswomen objected to a prohibition on displaying bare arms.

Several Senate Republicans have voiced opposition to the change in recent days. GOP Sen. Chuck Grassley, who was first elected to the US Senate in 1980, told CNN's Manu Raju, "what has been suggested stinks."

"It's unprecedented, and if you can't count on the majority leader of the United States Senate to uphold the decorum of the United States, who can you call on?" Grassley, of Iowa, said.

And Republican Sen. Susan Collins of Maine joked, "I plan to wear a bikini tomorrow to the Senate floor, and Chris Coons is gonna wear shorts, because there's no dress code anymore."

Fetterman on Tuesday mocked the Republican senators' objections, writing on X, "I figure if I take up vaping and grabbing the hog during a live musical, they'll make me a folk hero," an apparent reference to a recent controversy involving GOP Rep. Lauren Boebert. The Pennsylvania Democrat, who told CNN Raju earlier this week that while he was "grateful" for the new flexibility in his attire, has called the GOP's criticism "mystifying."

"I mean, there's certainly much more important kinds of issues we should be addressing instead of, like, how if I dress like a bum," Fetterman said.