Earlier in the day, Butts posted on Twitter a photo of the letter he sent to justice committee chair Anthony Housefather requesting an opportunity to participate at an upcoming meeting.
In the testimony before the House of Commons' justice committee on Wednesday, Wilson-Raybould said that she faced political pressure and "veiled threats" to drop a criminal prosecution against Montreal-based construction and engineering giant SNC-Lavalin. Butts was among those she accused of inappropriate pressure tactics. "A prime minister who doesn't know where the Liberal Party ends and where the government of Canada begins".
Butts, who resigned last week, says he believes he has evidence that will be of assistance to the committee in getting to the bottom the affair.
SNC-Lavalin is facing charges of corruption and fraud in connection with work it sought in Libya.
After his former justice minister's testimony this week, Mr Trudeau gave a press conference and denied wrongdoing, saying he had been thinking about potential job losses.
Trudeau said he "completely disagreed" with Wilson-Raybould later Wednesday night.
"I was sickened and appalled by [Wilson-Raybould's] story of inappropriate and, frankly, borderline illegal pressure brought to bear on her by the highest levels of Justin Trudeau's government", he said.
Wilson-Raybould resigned as minister of veterans affairs on February 12 in the wake of the SNC-Lavalin scandal. Wilson-Raybould has resigned, too.
"I believe the prime minister acted as he should of and vigorous conversations should have happened between the prime minister and the attorney general".
In none-Wilson-Raybould news...
Alyssa Bird, whose family is from Peguis First Nation, echoed Lariviere's point about feeling at odds with a government and legal system she says don't always represent the interests of Indigenous communities.
Trudeau's response appeared to be both a denial and an affirmation: "The prime minister said, 'No, no, no - we just need to find a solution'".
Conservative Leader Andrew Scheer has written a letter to the RCMP Commissioner, asking the force to investigate the SNC controversy, noting there may have been obstruction of justice.
An emergency debate is now scheduled for Thursday at 5 p.m. MST at the House of Commons.
When asked about this Thursday, Trudeau deflected by saying, again, that "had [former treasury board president] Scott Brison not stepped down, Jody Wilson-Raybould would still be minister of justice and attorney general of Canada".
If convicted in this case, SNC-Lavalin would not be allowed to bid on federal contracts in Canada for a decade.
Mr Trudeau's Liberal Party argues his time as premier has been successful, claiming 825,000 Canadians have been lifted out of poverty since he became Prime Minister in 2015. He reiterated that Chin "was acting entirely appropriately" in this matter. Wilson-Raybould said she resisted intervening because she wanted to uphold the principle of judicial independence and the rule of law, but officials ignored her repeated instructions to stop raising the issue. He did say that he did not direct Chin to do that.
"I have taken knowledge of her testimony and there are still reflections to have on next steps", he said.
Glen Motz, conservative MP for Medicine Hat-Cardston-Warner was also in attendance during Wilson-Raybould's testimony.
Native studies major Ashley Daniels, youth chief for the Southern Chiefs' Organization, said Wilson-Raybould sent a message.