HELENA, Mont. — The Montana House of Representatives took the extraordinary step on Wednesday of blocking a transgender lawmaker from the House floor for the remainder of the legislative session after an escalating standoff over her remarks on transgender issues in House debate.

The vote was 68 to 32 in the Republican-controlled chamber. The speaker adjourned the session immediately after the vote. The blocked lawmaker, Representative Zooey Zephyr, will still be allowed to cast votes during House proceedings for the remainder of the session, which concludes on May 5, but must do so remotely.

The move is the culmination of a weeklong battle between House leadership and Ms. Zephyr, who was barred from participating in deliberations on the House floor after she made impassioned comments during debate over a bill that would prohibit hormone treatments and surgical care for transgender minors. The bill has since been sent to Gov. Greg Gianforte, who has indicated that he will sign it.

It was the second eye-catching vote in a matter of weeks by a Republican legislative majority punishing dissent over a fractious issue. Earlier this month, Republicans in Tennessee ousted two Democratic state lawmakers over a gun control protest. Both have since been returned to their seats temporarily ahead of special elections later this year.

The incidents together reflect both the bitter divisions in the nation’s legislatures, and the willingness of Republicans with strong majorities to cite issues of civility and rules in the face of robust opposition from a Democratic minority.

Sue Vinton, the House majority leader, introduced the measure to discipline Ms. Zephyr, who was elected last year, saying that her actions “disrupted and disturbed the orderly proceedings of this body.”

Speaking from the floor, Ms. Zephyr said she was rising up in defense of her constituents from Missoula, of her community and “of democracy itself.”

“When the speaker asks me to apologize on behalf of decorum, what he is really asking me to do is be silent when my community is facing bills that get us killed; he’s asking me to be complicit in this Legislature’s eradication of our community,” she said.

“I refuse to do so. I will always refuse to do so,” she added.

The bill that Ms. Zephyr was condemning was one of a half-dozen similar bills targeting transgender youth that the Legislature had considered in the last week alone. And it comes amid an avalanche of similar legislation in Republican-controlled legislatures across the country.

Republican legislators have characterized transition care as harmful and experimental, arguing that young people should not be allowed to begin medically transitioning before they become adults.

But major medical organizations, including the American Academy of Pediatrics, support this care and say that bans pose serious mental health risks to young people, infringing not only on their rights but also on the rights of doctors and parents.

The furor over Ms. Zephyr began during an April 18 session, when the House was considering the ban on transitional care. Ms. Zephyr said that if Republicans passed such a ban, it would put “blood on your hands,” and that denying care would be “tantamount to torture.”

House Republicans have been threatening disciplinary action since that session. The Montana Freedom Caucus, a group of 21 conservative lawmakers, accused her of “attempting to shame the Montana legislative body” by using “hateful rhetoric.”

The caucus once again called for action against Ms. Zephyr on Monday and accused her of encouraging an “insurrection.”

Instead of issuing a formal reprimand, lawmakers had refused to call on Ms. Zephyr for any bill for consideration before the House, including environmental and economic measures, as well as transgender issues.

On Tuesday, Republican leaders canceled a planned session of the House, a day after protests led to arrests in the chamber. In a hasty news conference, Speaker Matt Regier blamed Ms. Zephyr for the conflict, saying that “the only person who is silencing Representative Zephyr is Representative Zephyr.”

Legislators started Wednesday’s session with a final reading of bills before turning to the status of Ms. Zephyr, who spoke from the House floor for the first time in a week. The gallery was closed to the public, but the session was broadcast online.

Ms. Zephyr remained unapologetic about her choice of words, and repeated her position.

“When I rose up and said, ‘There is blood on your hands,’ I was not being hyperbolic. I was speaking to the real consequences of the votes that we as legislators take in this body,” she said. She added that when Mr. Regier refused to let her speak, he was also “driving a nail in the coffin of democracy.”

Mr. Regier allowed for six representatives — three Democrats and three Republicans — to speak to the motion and allotted each five minutes to speak. Ms. Vinton, the House majority leader, closed her motion by saying that Ms. Zephyr’s conduct “cannot be allowed to stand.”

“Our constituents and our state deserve better. They deserve our full attention, and this institution and body deserve the respect of all its members,” Ms. Vinton said. “However it has not been respected, and we must regain the decorum of this body, not only now but also to set precedent for the future.”

Kelley Robinson, president of the Human Rights Campaign, one of the nation’s largest L.G.B.T.Q. advocacy groups, said in a statement on Wednesday that the vote in Montana “was part of a deeply disturbing trend of legislatures punishing leaders for using their voices to protest against discriminatory and dangerous legislation.”

Montana politics, once a competitive mix of Democrats and Republicans, has become much more conservative in recent years. Governor Gianforte, a Republican, is a fundamentalist Christian and a wealthy former software executive.

Republicans hold a supermajority in both the State House and Senate, and one conservative family from Flathead Valley in particular, the Regiers, wields great influence over both chambers. Keith Regier is the chairman of the Senate Judiciary Committee; his daughter, Amy, is chairman of the House Judiciary Committee, and his son, Matt, is the speaker of the House who has repeatedly refused to recognize Ms. Zephyr’s requests to speak on the floor.

Governor Gianforte’s family, however, is not as united when it comes to conservative policy. David Gianforte, the second oldest of his four children, has confronted his father about how the anti-transgender bills would harm the L.G.B.T.Q. community that he is a part of, The Montana Free Press reported.

The number of transgender and nonbinary people elected to public office nationally increased to at least 70 this year, from 25 in 2019, according to the LGBTQ+ Victory Fund, which supports those candidates. Of those officials, there are 14 sitting state legislators who are transgender or nonbinary, said Elliot Imse, the executive director of the LGBTQ+ Victory Institute, which is affiliated with the fund.

Now, two of those 14 have been formally disciplined. (The other is Representative Mauree Turner of Oklahoma, a nonbinary lawmaker who was censured last month after inviting a protester into their office; leaders of the State House said the lawmaker had harbored a fugitive wanted for questioning.)

Mr. Imse noted it was unusual for state legislatures to censure lawmakers. “That one in seven of our trans and nonbinary state legislators have been targeted is pure politics,” he said.

Over the past few years, Republican state lawmakers have introduced a wave of bills to regulate the lives of transgender youths by restricting the bathrooms they can use, the sports teams they can join and medical care they can receive.

These efforts have been particularly aggressive since start of the 2023 legislative season. This year, 11 states have passed laws prohibiting what’s known as gender-affirming care for young people.

Some conservative officials took up the issue earlier than others: Before this year, three state legislatures had enacted full or partial bans on gender-affirming care. But national conservative organizations have also seized on the issue, and the strong emotions around gender politics, to raise money and motivate voters.

In North Dakota, Doug Burgum, the Republican governor, signed a bill on Tuesday limiting transgender people’s use of certain restrooms, locker rooms and other facilities that align with their gender identity. And in Missouri, an unusually restrictive rule that would limit transgender care for adults, as well as for adolescents, could go into effect as soon as Thursday unless it is blocked by a judge.