One of Canadian PM Justin Trudeau's top ministers has quit saying she has lost confidence in the government's handling of a corruption inquiry. Treasury Board President Jane Philpott said: "I must abide by my core values, my ethical responsibilities, constitutional obligations." Mr Trudeau said he was disappointed by the resignation, but understood it. He has denied political meddling to shield engineering firm SNC-Lavalin from a bribery trial. Opposition Conservatives last week called on the Liberal PM to resign. A number of opinion polls indicate Mr Trudeau's popularity is slipping in the run-up to a general election scheduled for October. What did Jane Philpott say? The cabinet minister announced her decision to step down on Monday, posting her resignation letter detailing her "serious concerns" with "evidence of efforts by politicians and/or officials to pressure the former Attorney General to intervene in the criminal case involving SNC-Lavalin". "There can be a cost to acting on one's principles, but there is a bigger cost to abandoning them," she said in a statement. Her letter said it had become "untenable" for her to continue to serve in the cabinet. "It is a fundamental doctrine of the rule of law that our Attorney General should not be subjected to political pressure or interference regarding the exercise of her prosecutorial discretion in criminal cases," she wrote. "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 former family physician has held key portfolios in Mr Trudeau's cabinet - health, indigenous services and, until this week, treasury board president - since being elected in 2015. She will remain on as a Liberal member of Parliament. What about Mr Trudeau's response? In a short statement, Mr Trudeau thanked Ms Philpott for "her years of service and her dedication to Canadians". And commenting on the growing political scandal at a rally in Toronto later, the prime minister said: "Concerns of this nature must be taken seriously and I can ensure you that I am." AFP.