With trembling hands and a voice shaking through tears, the Manitoba senator said his behaviour that day was not acceptable.

"What I did was wrong, it was unprofessional, it was unbecoming," Plett said.

"I hold myself in higher regard than how I conducted myself that day. I never intended to cause harm or discomfort. I acknowledge that I lost my cool."

Plett apologized to Senate Speaker Raymonde Gagné as well as the leader of the Independent Senators Group, Sen. Raymonde Saint−Germain, and the group’s deputy leader, Sen. Bernadette Clement.

Saint−Germain and Clement said that on Nov. 9, after Clement moved to adjourn debate on an amendment being proposed for the Conservative private member’s bill, Plett "violently" threw his translation earpiece on his desk, charged across the Senate floor and began berating them in their seats.

Clement has said she had sought to adjourn debate because there were senators who weren’t in the room who wanted to speak about the amendment.

She was so frightened during the tirade that she "just froze," she said in an interview.

Plett then turned his wrath on the Speaker, arguing that she had recognized Clement ahead of other senators who were already standing and waiting to speak to the bill.

Saint−Germain rose on a point of privilege on Tuesday regarding the incident, arguing that her privileges as a senator had been breached. Clement supported that assertion.

Plett said Thursday he did not agree it was a point of privilege because no senators were prevented from exercising their rights to speak or vote in the chamber as a result of the events.

"What happened in this chamber on Nov. 9 and what some senators did on social media, offensive as they may be, is not covered by privilege," he said.

Saint−Germain and Clement also said some senators shared a social media post that they believe was the impetus for a barrage of hateful phone calls, including one that compelled Clement to leave her home on the advice of police.

Conservative House leader Andrew Scheer posted Clement’s photo and contact information, along with the details of Sen. Chantal Petitclerc, on X, the platform formerly known as Twitter. The post urged people to call them to ask why they were shutting down debate.

This all happened as furor over the carbon pricing bill brought the temperature up in the Senate.

The bill was introduced by Conservative MP Ben Lobb in 2022 and passed the House of Commons earlier this year with support from all parties except the Liberals.

The legislation would extend carbon−price exemptions for at least eight years to propane and natural gas farmers use to heat buildings and dry grain. After the final stage of debate in the Senate concludes, if the bill does not get amended, it is one vote away from becoming law.

Conservative Leader Pierre Poilievre, who is pledging to "axe" the carbon price if he is elected prime minister, launched an all−out campaign to get the bill passed following the Liberals’ decision last month to carve out heating oil from carbon pricing for three years.

The Liberals say that move was designed to give people more time and money to replace oil furnaces with electric heat pumps.

Conservatives, including Plett, have accused senators, including Clement, of conspiring with the Liberal cabinet to kill the bill, which they deny.

They say if the Senate amends the bill, it has to go back to the House of Commons for another vote, and the government could prevent that vote from happening.

On Wednesday in the Senate, Plett accused Environment Minister Steven Guilbeault of trying to pressure senators to vote against the bill, while Guilbeault was in the Senate answering questions from senators.

Plett demanded to know how many senators he has "pressured to vote against or gut this bill and deny our farmers the desperately needed tax relief," and whether his efforts are because he has promised to resign if another carbon−price carve−out happens.

Plett was referring to a comment the minister made earlier this month promising that "as long as I’m the environment minister, there will be no more exemptions to carbon pricing."

"Minister, will you keep your promise and resign if Bill C−234 is passed in its original form?" Plett asked.

"Isn’t that, minister, why you are calling senators to talk against this bill — because you’ve threatened to quit if it passes? Is your job more important to you, minister, than the livelihood of Canadian farmers and affordable food for Canadian families?"

Guilbeault said he did not say he would resign, and he hasn’t pressured any senators.

He has previously acknowledged calling about half a dozen senators to speak about the bill, but he insisted he is just giving them the government’s position, not pressuring them to vote against it.

"With all due respect, senator, there’s a world of difference between talking to someone and pressuring or whipping them into doing something or voting in a certain way," Guilbeault said.

"You asked me how many I pressured or whipped, and the answer is zero."

Conservatives, he accused, are the only ones whipping their caucus to vote a certain way on the bill.

"I’m not pressuring anyone, as opposed to the Conservative Party of Canada, who has launched a campaign against senators who don’t agree with them. I find that very troubling."

This report by The Canadian Press was first published Nov. 23, 2023.

Mia Rabson, The Canadian Press