Justin Trudeau’s administration is reeling as another senior Canadian official has walked out saying that the allegations of government interference in a major fraud case means she no longer has confidence in the prime minister. Jane Philpott, head of the treasury board, is the latest in a string of officials who have abandoned the young prime minister after allegations surfaced that senior officials attempted to head off the prosecution of engineering giant SNC-Lavalin. "I have been considering the events that have shaken the federal government in recent weeks and after serious reflection, I have concluded that I must resign as a member of Cabinet," Ms Philpott wrote on Twitter. "The solemn principles at stake are the independence and integrity of our justice system … Sadly, I have lost confidence in how the government has dealt with this matter and in how it has responded to the issues raised." The prime minister has tried to downplay the exit, telling a rally in Toronto that it was part of the healthy internal debate. "I know Ms Philpott has felt this way for some time. And while I am disappointed, I understand her decision to step down and I want to thank her for her service," he told the rally on Monday night. "We're allowed to have disagreements and debate. We even encourage it." Former justice minister and attorney general Jody Wilson-Raybould triggered the crisis for Trudeau's Liberal government in December. Last month, Ms Wilson-Raybould testified before the House of Commons' justice committee that Trudeau and his inner circle applied "inappropriate" pressure on her, including "veiled threats," to intervene in the prosecution of SNC-Lavalin. She said that from September to December 2018, officials "hounded" her to ask prosecutors to settle the case out of court. In 2015, SNC-Lavalin was charged with bribing Libyan officials for a decade from 2001 to secure government contracts under then ruler Muammar Qaddafi. Ms Wilson-Raybould, Canada's first indigenous justice minister, refused to bow to pressure and the trial was set. The move cost Ms Wilson-Raybould her job as she was shuffled to the office of veteran affairs before she resigned a month later. Then the prime minister’s top adviser and long-time friend Gerry Butts resigned. Eyes are on Mr Butts' testimony at a special session of the justice committee on Wednesday. He will likely respond to Ms Wilson-Raybould's version of the scandal offered to the committee last week. Ms Wilson-Raybould has said that in a meeting with Mr Butts on December 5, she raised the issue of pressure being exerted over the SNC-Lavalin trial. She says Mr Butts told her that she needed to find a solution. Mr Trudeau said he "completely disagrees" with his former attorney general's characterisation of events and insisted that he and his team were looking to safeguard upto 9,000 Canadian jobs, including in his own Quebec electoral district. The prime minister has insisted that he made clear the "decision around SNC-Lavalin was Wilson-Raybould's and hers alone to make". But with Ms Wilson-Rayboul and Ms Philpott out, Mr Trudeau has not only lost star performers but his gender-balanced cabinet is in jeopardy. “Because it’s 2015” is how he answered questions about his 50-50 line-up after a convincing election win four years ago. However, as state elections loom in October, he is sagging in the polls and party unity is strained. When Ms Wilson-Raybould walked on February 12, Ms Philpott was one of a few Liberal lawmakers who publicly supported her. And now Ms Wilson-Raybould returned the favour. "You are a leader of vision & strength & I look forward to continuing to work alongside you," she tweeted. The first time MP Celina Caesar-Chavannes also supported the move. “When you add women, please do not expect the status quo. Expect us to make correct decisions, stand for what is right and exit when values are compromised,” she said in a tweet. The prime minister defied the Liberal old guard and promised "real change" in the 2015 election, no small feat in a party infamous for solving problems in back room deals. Wilson-Raybould, Philpott and Caesar-Chavannes were all part of that "real change" as first time MPs. As well as Ms Wilson-Raybould being the first indigenous justice minister, Ms Caesar-Chavannes is one of only a handful of black lawmakers in Mr Trudeau’s caucus. Mr Trudeau’s Liberals hover at about 34 per cent in national polls. This is still enough to be competitive in the crowded electoral field but it’s trailing the Conservatives by 2 per cent. The federal election on October 21 is still months away but Ms Wilson-Raybold’s approval rating is heading in the opposite direction to the trailing Liberal party as a whole. Shachi Kurl, the executive director of the non-profit polling agency, Angus Reid Institute, called Ms Philpott’s resignation “a deluge, a massive splash, and one sure to keep this problem for the prime minister’s credibility and brand front and centre for Canadians at a time when Liberals are wishing it all away, in increasing vain”.