Prime Minister Justin Trudeau said in his view, Wilson-Raybould has been allowed to speak already about the issue at the heart of the matter.

A senior government source said the prime minister called an emergency strategy session with his senior staff and advisers about the possible need for a change in tone on the SNC-Lavalin affair.

Her resignation comes just two days before Gerald Butts, the prime minister's former right-hand man, is set to testify on the matter before the justice committee.