Nashville, Tennessee CNN — The Tennessee House of Representatives is scheduled to vote Thursday on removing from office three Democratic lawmakers who protested on the chamber floor with a bullhorn to call for gun reform following last month’s school shooting in Nashville – and now are accused of breaking House rules.

Protesters flooded the state Capitol as the legislators were set to take up three resolutions filed by GOP lawmakers Monday seeking to expel Reps. Gloria Johnson of Knoxville, Justin Jones of Nashville and Justin Pearson of Memphis, a step the state House has taken only twice since the 1860s.

The three lawmakers led a protest on the House floor last Thursday without being recognized, CNN affiliate WSMV reported, using a bullhorn as demonstrators at the state Capitol called on lawmakers to take action to prevent further gun violence. The protest came after three 9-year-olds and three adults were killed in a mass shooting on March 27 at The Covenant School, a private Christian school. Each was removed from their committee assignments following last week’s demonstrations.

“It’s morally insane that a week after a mass shooting took six precious lives in my community here in Nashville, my colleagues on the other side of the aisle, their first action is not to take actions to rein in this proliferation of weapons of war in our streets, but it’s to expel their colleagues for standing with our constituents,” Jones told “CNN This Morning” on Wednesday.

“This is not just about losing my job,” he added, saying constituents of the three representatives “are being taken and silenced by a party that is acting like authoritarians.”

The House has expelled only two lawmakers in the last 157 years: In 1980, after a representative was found guilty of accepting a bribe while in office, and in 2016, when another was expelled over allegations of sexual harassment.

This week, Speaker of the House Cameron Sexton, a Republican, said the three Democrats’ actions “are and always will be unacceptable” and broke “several rules of decorum and procedure on the House floor.”

Sexton said peaceful protestors have always been welcomed to the capitol to have their voices heard on any issue, but that the actions of the Democratic lawmakers had detracted from that process.

“In effect, those actions took away the voices of the protestors, the focus on the six victims who lost their lives, and the families who lost their loved ones,” Sexton said in a series of tweets Monday.

“We cannot allow the actions of the three members to distract us from protecting our children. We will get through this together, and it will require talking about all solutions,” Sexton said.

The move to expel the trio drew protesters to the Capitol Thursday morning, with many wanting to express both their opposition to the lawmakers’ removal from office – chants of “We stand with the Tennessee three,” were heard outside – as well as support for gun reform legislation.

To some, the vote to expel Johnson, Jones and Pearson was a distraction from the real issue: Keeping children safe.

“I want people to know this is not a political issue, it’s a child issue,” Deborah Castellano, a first-grade teacher in Nashville, told CNN. “If you wash away Democrat, Republican, it’s about kids and do we want them to be safe or not. I will stand in front of children and protect as many as I can with my body … but we shouldn’t have to, and those kids shouldn’t be afraid.”

Paul Slentz, a retired United Methodist pastor, knows two of the lawmakers personally, he said, adding it was wrong for them to face a vote for their expulsion.

“They’re good people,” Slentz told CNN affiliate WSMV in an interview outside the Capitol. “They have strong moral convictions. They are people of faith.”

Expulsion requires two-thirds vote

Each of the resolutions says the lawmakers “did knowingly and intentionally bring disorder and dishonor to the House of Representatives,” saying they “began shouting without recognition” and “proceeded to disrupt the proceedings of the House Representatives” for just under an hour Thursday morning.

The resolutions seek to remove the lawmakers from office under Article II, Section 12 of the Tennessee Constitution, which says, in part, the House can set its own rules and “punish its members for disorderly behavior, and, with the concurrence of two-thirds, expel a member.”

Republicans control the Tennessee House of Representatives by a wide margin, with 75 members to Democrats’ 23. One seat is vacant.

The code allows for the appointment of interim members of the House until the seats of the expelled are filled by an election.

Pearson has acknowledged he and his two colleagues may have broken House rules, both in a letter sent to House members this week and in an interview with CNN on Wednesday, acknowledging they “spoke out of order” when they walked to the well of the House.

“We broke a House rule,” he said, “but it does not meet the threshold for actually expelling members of the House who were duly elected by their district, who sent us here to serve, and now they’re being disenfranchised by the Republican party of the state of Tennessee.”

House Democrats expressed solidarity with Johnson, Jones and Pearson in a statement, while Rep. Sam McKenzie, of the Tennessee Black Caucus of State Legislators, called the move “political retribution.”

“We fundamentally object to any effort to expel members for making their voices heard to end gun violence,” McKenzie said.

The move to expel the lawmakers also drew condemnation from the American Civil Liberties Union of Tennessee, whose executive director, Kathy Sinback, called expulsion “an extreme measure” infrequently used, “because its strips voters of representation by the people they elected.”

“Instead of rushing to expel members for expressing their ethical convictions about crucial social issues,” Sinback said, “House leadership should turn to solving the real challenges facing our state.”