Several Republicans refused to wear their masks on the House floor Tuesday afternoon in a rebellion against Speaker Nancy Pelosi's (D-Calif.) refusal to lift the mandate, despite the threat of hefty fines for the rule violation.

What are the details?

Politico reported ahead of the protest that Rep. Brian Mast (R-Fla.) announced during a GOP conference meeting earlier in the day that he is "done" wearing masks, and will refuse to wear one on the House floor.

Mast confirmed his plan to the outlet, and said "many" of his colleagues agreed to do the same.

Rep. Thomas Massie (R-Ky.) tweeted from the House floor later, "We've had enough. We are refusing to wear our masks on the floor during this vote in spite of Pelosi's threat to take $500 from each of us. Her rule is not based on science. All you need to know is the mask rule has only ever applied to members when they can be seen on TV !"

We've had enough. We are refusing to wear our masks on the floor during this vote in spite of Pelosi's threat to ta… https://t.co/kpz2iqdjft
— Thomas Massie (@RepThomasMassie) 1621369233.0

Georgia Rep. Marjorie Taylor Greene (R) later tweeted out a photo of herself along with Reps. Mary Miller (R-Ill.), Ralph Norman (R-S.C.) and Massie declaring, "#FreeYourFace Masks are oppressive and nothing but a political tool. End the oppression!"

#FreeYourFace Masks are oppressive and nothing but a political tool.End the oppression! https://t.co/EBvCtBpE6u
— Marjorie Taylor Greene 🇺🇸 (@mtgreenee) 1621369262.0

Greene also posted a picture of herself along with seven other Republicans outside the steps of the Capitol, tweeting, "Proud to join these Patriots for a peaceful protest on the House floor against mask mandates!"

Proud to join these Patriots for a peaceful protest on the House floor against mask mandates!#FreeYourFace😁 https://t.co/NSgC5Hfj4E
— Marjorie Taylor Greene 🇺🇸 (@mtgreenee) 1621377551.0

Journalist Jordan Schactel reported that other GOP members who joined the protest included Reps. Lauren Boebert (Colo.), Chip Roy (Texas), Bob Good (Va.), Beth Van Duyne (Texas), and Greg Steube (Fla.).

House Minority Leader Kevin McCarthy (R-Calif.) is expected to introduce a motion on the topic on Wednesday, but sources told Politico that the "language is still being worked out."

What's the background?

Pelosi insists on keeping her mask mandate in place — threatening members with $500 fines on a first offense and $2,500 for a second — despite the CDC announcing last week that fully vaccinated Americans can stop wearing masks indoors in most places.

The speaker's move was condemned by several GOP lawmakers, including Mast, who tweeted that her action was "not about science" and "all about power."

The Hill pointed out that the Senate never had a mask mandate in place, and both Senate Majority Leader Chuck Schumer (D-N.Y.) and Senate Minority Leaders Mitch McConnell (R-Ky.) ditched their masks following the CDC's new guidance.