First, to go back further, the government indicated that it was considering such a vehicle as an infrastructure bank as it came into office. Since that period, it has been working collaboratively on this concept with various ministries, including the Department of Finance and the Department of Infrastructure. It was a suggestion that came out of the growth council as a potential tool that could support growth and other policy objectives, and that fed into the government as one piece of advice as the government made its decision on the Canada infrastructure bank. That was only one of many extensive consultations that led to that particular announcement.
On May 18th, 2017. See this statement in context.