WATCH: PM Trudeau addresses Jane Philpott resignation over SNC-Lavalin scandal

Prime Minister Justin Trudeau said he's disappointed over the resignation by one of his top cabinet members over the way the SNC-Lavalin scandal has been handled, but that he understands her decision.

Trudeau spoke at a climate change rally Monday night in Toronto, after Jane Philpott announced she would be leaving her post as Treasury Board President.

"I know Ms. Philpott has felt this way for some time," he said. "I want to thank her for her service."

After his first comments were disrupted by a heckler, he continued his praise for Philpott, citing her work on boil water advisories on reserves and working on the Phoenix pay system.

"In a democracy like ours and in a space where we value our diversity so strongly, we're allowed to have disagreements and debate," he said. "This matter has generated an important discussion."

"Concerns of this nature must be taken very seriously and I can assure you that I am."

Trudeau also said he appreciates the work the justice committee is doing in its questioning of those involved in the scandal, as his former principal secretary and political confident Gerald Butts is set to testify on Wednesday.

"There are more questions still to answer and more to be said in the coming days and weeks, but at the same time my friends, we need to keep in mind, the bigger picture behind this fantastic movement we have built and continue to build."

Trudeau did not take questions from reporters.

Earlier in the day, Philpott said she had lost confidence in how the government has dealt with the matter.

Last week, Jody Wilson-Raybould testified before the committee about how she had felt inappropriately pressured by PMO staff and cabinet colleagues to intervene in the criminal charges facing SNC-Lavalin.

The former attorney-general said that she would not interfere in pushing the director public prosecutions to sign a deferred prosecution agreement with the company.

Philpott is close friends with Wilson-Raybould and was one of the most respected members of the cabinet, having held previous portfolios such as health and Indigenous Services.

"I must abide by my core values, my ethical responsibilities and constitutional obligations," she said in her resignation letter. "There can be a cost to acting on one's principles, but there is a bigger cost to abandoning them."

Both Philpott and Wilson-Raybould are remaining as MPs and Trudeau still hasn't given a firm answer as to whether Wilson-Raybould will remain as a member of the caucus before the next election.