Paul Keating has launched a withering attack on Bob Hawke, Labor's longest-serving prime minister, asserting that he assumed the role of leading the government for five years of Mr Hawke's almost nine years in office.

"To be prime minister of Australia, you have got to be lucky," Mr Keating told a Canberra gathering.

Former prime minister Paul Keating with Gareth Evans at Wednesday's book launch in Canberra. Credit:Alex Ellinghausen

"To be prime minister for Australia, with five years down time, you've got to be more than lucky - and history deserves to know that that's the way it was."

The occasion was the launch of Gareth Evans' A Cabinet Diary of two of those years, from 1984 until 1986, and Mr Keating used passages of the book to flesh out his own critique of Mr Hawke's failings.