WASHINGTON - In one of the most extraordinary scenes in years on the US House floor, Democrats staged a dramatic sit-in on Wednesday, demanding that the Republican-led Congress address gun violence following the Orlando nightclub massacre.

The lawmakers’ action, which earned praise from President Barack Obama, signaled what is likely to be a protracted election-year battle over firearms -- perennially a hot-button campaign issue in the United States.

"We have to occupy the floor of the House until there is action," said Democratic Congressman John Lewis -- a civil rights icon who marched with Reverend Martin Luther King Jr in the 1960s -- just before he and dozens of colleagues sat down on the carpeted floor in the well of the chamber.

The interruption came just as the House presiding officer moved to declare the body in recess.

"No bill, no break!" the lawmakers chanted after the presiding officer and staff left the chamber.

Even with lights dimmed and microphones turned off, several dozen lawmakers carried on, with the sit-in entering its fifth hour by 4:00 pm local time.

"No more Orlandos! No more Auroras! No more victims!" shouted Congresswoman Debbie Wasserman Schultz, her voice cracking as she addressed colleagues to loud cheers.

US lawmakers, mainly Democrats, have introduced several bills in recent years aimed at reducing gun violence, including legislation to expand background checks -- a provision that has broad support among the voting public. But none has passed Congress.

"Who has to be shot, and how many have to die before we do anything?" asked Robin Kelly, a congresswoman from Illinois.

"It’s not a colleague, Gabby Giffords. It’s not children in an elementary school. It’s not people praying in a church," she added.

"This is embarrassing."

House Speaker Paul Ryan has refused to schedule a vote for gun control legislation in the aftermath of the Orlando shooting that left 49 people dead.

The chamber was scheduled to wrap up business today before going on its vacation ahead of the Fourth of July holiday.

"If there’s no bill to vote on, there should be no congressional break," Democrat Earl Blumenauer told the House.

The sit-in, which quickly grew to about 100 members, drew the attention of the White House.

"Thank you John Lewis for leading on gun violence where we need it most," Obama posted on Twitter.

"This is what real leadership looks like," Democratic White House hopeful Hillary Clinton added in her own tweet.

’Give us a vote’

With the C-Span cameras turned off during the recess, the public broadcaster responsible for covering congressional sessions enacted a creative workaround, broadcasting live video from social media applications Periscope and Facebook, filmed by a lawmaker on the House floor.

It was the first time C-Span aired live social media footage from the House floor -- where taking pictures and video is against the rules.

There were extraordinary scenes in the chamber.

Congresswoman Tammy Duckworth, a former US Army helicopter pilot who was wounded and lost both legs in Iraq, sat with her colleagues on the carpet of the well, her prosthetics removed, her wheelchair empty beside her.

Top House Democrat Nancy Pelosi joined the insurgents, then led several lawmakers and gun violence survivors and relatives outside onto the Capitol steps.

"Give us a vote," she demanded of Ryan.

"A moment of silence? We want a moment of truth. We want a time of action to follow it."

Earlier this week, the US Senate voted on four gun control amendments -- two from Democrats and two from Republicans -- after Senate Democrat Chris Murphy delivered a 15-hour floor speech demanding votes on gun control.

The Senate rejected all four measures, but lawmakers crafted a bipartisan compromise bill aimed at preventing terror suspects and people on no-fly lists or FBI watchlists from buying a firearm.

The bill’s sponsors said Senate leaders assured them a vote on the legislation.

Murphy and more than a dozen other Democratic senators, including popular, firebrand Elizabeth Warren entered the chamber to express their solidarity.

"You cannot stand down at a moment of peril for this country," Murphy told MSNBC.— AFP