WASHINGTON — Republican members of Congress were noticeably reluctant to wear masks on the House floor Thursday, sparking a sharp debate with Democrats, who readily accepted the federal guidance.

As lawmakers gathered for a morning debate on creating a coronavirus stimulus oversight committee, the GOP side of the chamber largely left their mouths and noses uncovered, while some Democrats, including House Speaker Nancy Pelosi, dropped their coverings while speaking.

Democrats nearly all entered the chamber wearing either bandannas or masks — of many colors. At least two were orange. One wore a mask embroidered with a sparkly sequin American flag.

The sole Democratic exception as of mid-afternoon was recovered coronavirus patient Rep. Joe Cunningham of South Carolina. He later put on a mask after The Post contacted his staff for comment. His aides did not comment.

House Rules Committee Chairman Jim McGovern (D-Mass.) lashed into his Republican colleagues who chose not to cover up after Rep. Jim Jordan (R-Ohio) spoke. Jordan, who coughed repeatedly while awaiting his turn to speak, did not wear a mask while seated on the floor, or at the lectern.

“People can do what they want to do,” McGovern scolded. “But while we all want to show how fearless we are, we should be mindful of the people that are surrounding us. And so until I’m advised otherwise, I’m going to keep my mask on.”

“While face coverings are not mandatory, they are certainly recommended,” McGovern said. “The Office of the Attending Physician has also advised that a face cover will produce a minimal reduction in sound when using a microphone. The face covering is most useful in reducing viral spread while speaking.”

Meanwhile, Republicans argued against the proposed new oversight committee, saying it would be a politicized weapon to attack President Trump. Later Thursday, lawmakers will vote on a half-trillion-dollar package of small-business loans, hospital aid and testing funds.

The House gathering was the first since March 27, when masks were rare or non-existent on the floor, as US health officials said at the time that masks were ineffective for the public to protect against the virus. The health guidance about-faced this month, with federal officials advising face coverings as an optional measure to prevent spread of the virus.

In several Asian countries, authorities credit universal mask wearing with preventing major outbreaks of COVID-19. In Taiwan, which has a larger population than New York, there are about 400 cases of the coronavirus after early widespread mask wearing.

Minority Leader Kevin McCarthy (R-Calif.) and Minority Whip Steve Scalise (R-La.) arrived on the House floor without masks, as did many GOP peers.

“Nice mask!” a colleague told Scalise.

“Thanks! I wear it for Halloween, too!” the second-ranking Republican said, laughing uproariously.

Those who did not wear masks included Reps. Jack Bergman (R-Mich.), Andy Biggs (R-Ariz.), James Comer (R-Ky.), Louie Gohmert (R-Texas), Brett Guthrie (R-Ky.), Jody Hice (R-Ga.), David Kustoff (R-Tenn.), Michael McCaul (R-Texas), Tom McClintock (R-Calif.), Cathy McMorris Rodgers (R-Wash.) and Chip Roy (R-Texas).

Some Republicans did wear masks, and the number who did increased around noon when lawmakers pivoted to debating the fourth large coronavirus bill.

GOP Reps. Kevin Brady of Texas, Steve Chabot of Ohio, Tom Cole of Oklahoma, Debbie Lasko of Arizona and Thomas Massie of Kentucky were among those who wore masks.

Aside from Cunningham, the closest to an unmasked Democrat was Rep. Richard Neal of Massachusetts, who wore a mask tied around his neck. It did not appear that Neal ever raised the mask onto his face.

During House votes last month, many New York Democrats ignored guidance from the Centers for Disease Control and Prevention, which urged a 14-day self-quarantine for people recently in the New York metro area.