A story about a female Capitol Hill reporter unexpectedly barred from the House Speaker’s Lobby for wearing a sleeveless dress is emerging as Washington’s hottest controversy -- with some veteran journalists now trying to take the blame off Speaker Paul Ryan and saying the rules have long been in place.

The controversy apparently started with a story by CBS News about the bare-shouldered reporter being told by a guard that she couldn’t enter the area, adjacent to the House floor. So she tried unsuccessfully to cover her shoulders by creating sleeves with pages she ripped from her notebook.

The flap over the dress code in the area, where reporters often catch House members exiting the floor for an interview, frequently emerges during the hottest days of summer.

This summer, some publications have suggested the ban on bare-shouldered tops and open-toed shoes for women was instituted or being enforced by Ryan, R-Wis.

However, such rules appear to have been in place for a long time, though apparently subject to different interpretations and enforcement.

House rules state lawmakers must “dress appropriately, which has traditionally been considered to include a coat and tie for male members and appropriate attire for female members.”

Another part of the rules makes clear that members should not wear overcoats or hats on the floor while the House is in session.

“Don't hang this on @SpeakerRyan I've covered Congress & have seen women and men incl (members) booted for breaking the dress code,” National Press Club President Jeff Ballou tweeted Friday.

One possible explanation is that Ryan recently reminded members to wear “appropriate business attire on the House floor.”

In the online CBS story posted Thursday, Haley Byrd, a congressional reporter for Independent Journal Review, reportedly said she was kept out of the lobby in May because she was wearing a sleeveless dress.

"I was just trying to pass through the area to reach another hallway, but I was told I was violating the rules,” Byrd is quoted as saying. “They offered to find a sweater for me to put on, so it wasn't some tyrannical end of free press, but I opted to just go around instead. But recently they've been cracking down on the code, like with open-toed shoes."

NBC News’ congressional reporter Kasie Hunt said over a series of tweets earlier this week: “This is simply wrong. The Speakers' Lobby dress code has been this way for decades. Can be argued it should change -- but let's be factual,” and “As long as I've worked on the Hill (on and off for 10+ years), it's been enforced. Including when Nancy Pelosi was Speaker.”

Fox News’ Chad Pergram contributed to this story.