A drained and dwindling group of Democrats vowed early Thursday to continue pressing for gun-safety legislation in the wake of the Orlando massacre — as they carried their dramatic House floor sit-in past daybreak and disrupted the business of Congress.

Republicans who control the chamber slammed the sit-in and adjourned the chamber around 3:15 a.m. until after the Fourth of July.

By 6:30 a.m. Thursday — 19 hours after the sit-in started — some 16 Democrats remained, including Minority Leader Nancy Pelosi, giving speeches and vowing to never retreat in their drive to curb firearm violence.

“While the Americans don’t always expect us to win, they do expect us to fight,” said Rep. Al Green (D-Texas) as dawn broke and the few remaining lawmakers sat beneath empty visitor galleries. “We demonstrated to the American people why we can’t get votes on common-sense safety measures.”

When Republicans left hours earlier, Democrats remained on the House floor, shouting, “No bill, no break!” — referring to the July Fourth holiday — and waving papers with the names of gun victims written in black.

Rep. Maxine Waters of California said she was prepared to stay “until Hell freezes over.”

The House drama began after Democrats took over the chamber’s proceedings Wednesday — prompting Republican Speaker Paul Ryan to gavel the House into session late at night.

Ryan (R-Wis.), who dismissed the theatrical protest as a “publicity stunt,” refused to allow votes on two bills demanded by Democrats: one to expand background checks and another that prevents those on terror watch lists and no-fly lists from buying guns, AFP reported. He said the bills would take away people’s constitutional rights and deprive them of due process.

But with a crowd cheering them on from outside the Capitol and many more following the proceedings on social media, Democrats declared success in dramatizing the call for action to combat gun violence.

“Just because they cut and run in the dark of night, just because they have left doesn’t mean we are taking no for an answer,” said Pelosi (D-Calif.).

Rep. John Lewis (D-Ga.), who had participated in the civil rights sit-ins in the South in the 1960s, said Democrats had “crossed one bridge.”

“We have other bridges to cross,” he said, adding that Democrats “made a down payment on ending gun violence” in America. “We will continue to fight. . . . When we come back in July, we’ll start all over again.”

Rep. Katherine Clark (D-Mass.), who is credited with coming up with the idea and helping to recruit Lewis, said he “gave us all the resolve and the grit and determination to see this through when we are back in July,” the Washington Post reported.

The sit-in, which began at 11:29 a.m. Wednesday, included more than 100 House Democrats taking to the floor, waving signs naming victims of gun violence and singing “We Shall Overcome.”

During the sit-in, the cameras normally used for C-SPAN broadcasts, which are controlled by the Republican House leadership, were turned off, as were microphones. C-SPAN carried footage via livestreams from members’ smartphones, the paper reported.

Throughout the day, the Democrats assailed the GOP’s refusal to bring gun-control measures to the floor. They taped rainbow-colored signs that said “Disarm hate” to all of the speaking podiums.

As the sit-in dragged into the night, they brought pillows, blankets and snacks to prepare for the long haul.

At 10 p.m. Wednesday, an exasperated Ryan took to the floor to call a vote on an unrelated measure, hoping to end the sit-in, but the Democrats chanted “Shame!” at him.

By 2:30 a.m., Republicans moved up a vote to provide funding for the Zika virus — a bill Democrats haven’t agreed to.

“Democrats can continue to talk, but the reality is that they have no end-game strategy … and no stunts on the floor will change that,” said AshLee Strong, Ryan’s press secretary, the paper reported.

Outside the Capitol, Lewis addressed a group of about 150 gun-control advocates on the Capitol lawn.

“By standing here tonight, by standing with us, you’re bearing witness to the truth; you must never, ever give up or give in or give out,” he said, the Washington Post reported. “We got to stop the violence and do something about the proliferation of guns.”

Pressure had been building on both sides of the Capitol in the wake of the shooting rampage at the Pulse gay nightclub in Orlando, Florida, that killed 49 people and injured 53 others. The assailant, Omar Mateen, also died in the incident.

The mass shooting followed similar tragic incidents including the school shooting in Newtown, Connecticut.

The agitation for action caused a Senate filibuster last week and led to the chaos on the House floor that lasted well into Thursday.

Republicans had staged a similar protest in 2008. At the time, Democrats controlling the House turned off the cameras amid a GOP push for a vote to expand oil and gas drilling. Republicans occupied the floor, delivering speech after speech after Pelosi, then the House speaker, sent lawmakers bolting to their August recess. Pelosi at that time had ordered the cameras turned off.

With Post wires