Canadian Prime Minister Justin Trudeau is facing renewed calls to resign after a secretly recorded telephone call between two senior figures in his administration was made public, escalating claims he tried to shield an allegedly corrupt firm from prosecution.

The 17-minute call took place in December between Jody Wilson-Raybould, then the attorney general, and Michael Wernick, then Canada’s most senior civil servant, about the engineering company SNC-Lavalin, which was accused of paying bribes to Libyan officials.

Mr Wernick is heard in the audio telling Ms Wilson-Raybould that Mr Trudeau is interested in having the firm avoid criminal prosecution in favour of paying a fine, repeatedly saying that the prime minister is in a “pretty firm” frame of mind on the issue.

"I think he is going to find a way to get it done one way or another. He's in that kind of mood. I wanted you to be aware of that,” Mr Wernick is heard saying at one point.

Ms Wilson-Raybould in turn pushes back, raising concerns that the conversation could amount to “political interference” and an attempt to breach her “prosecutorial independence”. She declined to push for the prosecution to be dropped.