Gerald Butts, Prime Minister Justin Trudeau's former top aide, testified Wednesday there was no intention on the government's part to pressure Jody Wilson-Raybould to change her mind on the criminal prosecution of SNC-Lavalin, and official engagements were meant only to ensure she had the full facts on the impact of a potential conviction.

"I am firmly convinced that nothing happened here beyond the normal operations of government," he told the Commons justice committee.

At all times, he said, the prime minister made it clear that the decision to prosecute or not was Wilson-Raybould's alone to make as attorney general, but that the issue merited robust discussion and consideration because there were so many jobs at risk.

Butts said highly trained legal staff worked on the file to ensure no line was crossed in engagements with the then-attorney general. He said the objective was to underscore the impact of a prosecution, including the thousands of jobs at stake.

Those discussions continued because Wilson-Raybould never informed the prime minister or other officials in writing of her decision, he said, leading people to believe that new information could come to light that would affect the decision. Butts said he first learned her decision was final in her committee testimony last week.

Butts also insisted Wilson-Raybould's move to the Veterans Affairs portfolio in a Jan. 14 cabinet shuffle had nothing to do with the SNC-Lavalin matter.

He said he did not want to quarrel with or discredit Wilson-Raybould but would offer a "different version of events," backed up by his own notes, text messages and conversations with other officials.

"It was not about second-guessing the decision. It was about ensuring that the attorney general was making her decision with the absolute best evidence possible," Butts said.

He said officials always understood the final call on whether to override a decision by the independent director of public prosecutions rested with Wilson-Raybould as attorney general.

Because of the enormous impact of her decision, officials suggested getting an independent opinion from a former retired Supreme Court justice such as Beverley McLachlin, the former chief justice.

Butts said if Wilson believed something inappropriate was happening, she had many opportunities to inform the prime minister, but did not. The allegations did not come to light until after the cabinet shuffle, he said.

"If this was wrong, and wrong in the way it is alleged to have been wrong, why are we having this discussion now and not in the middle of September, or October, or November, or December?"

Later, he said: "I firmly believe that nothing inappropriate occurred here and nothing inappropriate was alleged to have occurred until after the cabinet shuffle."

The Liberal-dominated committee rejected an NDP motion to call Wilson-Raybould back to respond to Butts. Wilson-Raybould told CBC News that she would return if asked.

"With respect to the committee, I would of course make myself available to the Committee if requested to give additional testimony, to answer any further questions and to provide further clarity that may be required," she said in an email. "I will note, as I indicated at the time, my statement to the committee was not a complete account but only a detailed summary."

Conservative Leader Andrew Scheer said today's testimony does nothing to disprove the claim that Trudeau and his highest-ranking officials tried to politically interfere in the criminal prosecution of SNC-Lavalin by "bullying and threatening" Wilson-Raybould.

"It continued, despite Ms. Wilson-Raybould rendering a final decision and telling the Prime Minister's Office to back off. And when she wouldn't do what Mr. Trudeau wanted her to do, she was fired," he said in a statement.

"The bottom line is Justin Trudeau tried to subvert the rule of law to win elections and benefit his friends. Nothing Canadians heard today conflicts with that."

Butts disputed Wilson-Raybould's testimony last week — that she believed she was shuffled over the SNC-Lavalin matter — insisting Trudeau tried hard to avoid a shuffle because he was "happy with his team."

The prime minister tried unsuccessfully to have Scott Brison change his mind about resigning as Treasury Board president, Butts said. Having moved Jane Philpott to the position, he said, Trudeau asked Wilson-Raybould to take on the Indigenous Services portfolio, which she refused.

Butts said the PMO was surprised by her refusal, as cabinet decisions are "not the product of shared decision-making." But he said he tried to reassure her that her eventual move to Veterans Affairs had nothing to do with the SNC-Lavalin matter.

"I was deeply concerned by what the minister was saying. I tried to counter her misapprehensions with repeated, and believe me, honest efforts," he said. "In the end, I was unable to do so, and here we are today."

Wilson-Raybould testified last week that the week before the cabinet shuffle, she received a call from Trudeau advising her she was being moved from the justice portfolio. She would not divulge details of any communications regarding the shuffle but said she believed the reason she was moved from justice was "because of the SNC matter."

Butts said he takes responsibility for the "breakdown" in trust with Wilson-Raybould, and ultimately with Philpott.

Philpott resigned from cabinet Monday, citing a loss of confidence in the government's handling of the SNC-Lavalin affair.

The committee resumed with testimony from Clerk of the Privy Council Michael Wernick and Nathalie Drouin, the deputy justice minister and deputy attorney general. CBCNews.ca is carrying it live.

Butts resigned Feb. 18 amid a growing controversy over alleged political interference related to a decision to prosecute SNC-Lavalin for bribery charges related to contracts in Libya.

In explosive testimony last week, Wilson-Raybould said she faced intense pressure and veiled threats from 11 officials from the Prime Minister's Office and elsewhere in government.

She said she was contacted through phone calls, meetings and text messages.

"For a period of four months from September to December 2018, I experienced a consistent and sustained effort by many people within the government to seek to politically interfere in the exercise of prosecutorial discretion in my role as the attorney general of Canada in an inappropriate effort to secure a Deferred Prosecution Agreement (DPA) with SNC-Lavalin," Wilson-Raybould testified.

She said she met with Butts on Dec. 5 to speak about a number of things, including SNC-Lavalin and the "barrage" of people "hounding" her and her staff.

Towards the end of that meeting at Chateau Laurier, she said, she told Butts that people must stop talking to her about SNC as she had made up her mind and the engagements were inappropriate.

"Gerry then took over the conversation and said how we need a solution on the SNC stuff. He said I needed to find a solution," Wilson-Raybould testified.

Today, Butts offered a very different account, recalling a two-hour dinner followed by congenial exchanges. He said he considered Wilson-Raybould a friend.

The former attorney general said she always believed that Butts was speaking with the "full authority" of the prime minister.

Wilson-Raybould also testified about a conversation her then chief of staff Jessica Prince had with Butts and Katie Telford, where they seemed "quite keen" on the idea of retaining an ex-Supreme Court justice to get advice. She testified that Prince said Telford believed it would give them "cover" in the business community and the legal community, and allow the prime minister to say they were doing something.

"She was like, 'If Jody is nervous, we would of course line up all kinds of people to write op-eds saying that what she is doing is proper,'" Wilson-Raybould said, reading from a text from Prince.

Butts said the discussion was not meant to exert pressure but to seek to understand the "reticence" in gaining external advice, which he considered to be sound public policy.

Conservative justice critic and deputy leader Lisa Raitt called the decision not to bring back Wilson-Raybould "atrocious."

"The reality is there are stark contradictions and one of them isn't telling the full story," she said. "And we need to find which one it is."

In his opening statement, Wernick said he was "profoundly disappointed" by the fact that his testimony last week was characterized by some as partisan. He repeated his claim that he never applied inappropriate pressure on, or issued veiled threats against, Wilson-Raybould.

"The minister experienced lawful advocacy to consider doing something lawful in the public interest," he said.

In testimony peppered with testy exchanges with opposition MPs, Wernick said Wilson-Raybould's decision not to intervene was not considered final.

"As a matter of law, the decision is never final because she could always take into consideration public interest considerations and was able to take into account new information," he said.

Drouin said there was never any obligation on the part of the attorney general to present a written statement on her decision, or to provide reasons for it.

She said the Privy Council Office asked her department Oct. 19 for an opinion on the potential impacts of a criminal conviction on SNC-Lavalin, but that legal opinion was not provided to the PCO "at the request of the minister's office."

The justice committee reconvenes March 19 — the day Finance Minister Bill Morneau tables his next budget — to debate whether to call more witnesses.