OTTAWA (Reuters) – Canadian Prime Minister Justin Trudeau on Monday changed his cabinet for the third time in three months in response to a crisis caused by the resignation of a minister who later alleged inappropriate conduct by officials.

In a surprise move, Trudeau named backbench Liberal legislator Joyce Murray to the post of Treasury Board President, where she will be in overall charge of government spending.

It is the first federal cabinet post for Murray, 64, who had previously been a provincial government minister in British Columbia.

Murray replaces Jane Philpott, who quit on March 4 in protest over how the government was handling a corruption case involving SNC-Lavalin Group Inc, a major construction company.

Philpott expressed unhappiness over allegations that government officials pressured former Justice Minister Jody Wilson-Raybould last year to help Montreal-based SNC-Lavalin avoid a criminal trial.

Wilson-Raybould, who was demoted in January, resigned from Trudeau’s cabinet the next month. Trudeau’s closest personal aide quit shortly afterwards.

Polls show the crisis could derail the Trudeau government’s chances of being reelected in October.

Earlier this month, Trudeau denied he or his officials had interfered in Canada’s judicial system, and he offered no apology.