Flesher and Zarzeski in their recent examination of the North American origins of value-for-money auditing highlight the reluctance of public sector auditors in Australia, New Zealand and Britain to assume operational auditing as part of their mandate until the 1970s, and then only gradually. It is suggested here that the very different constitutional forms of Westminster and American governments and their associated conventions denied auditors- general the authority to follow the American example. In their paper Flesher and Zarzeski also recognise Canada as an unusually early adopter of operational auditing, although suggesting that actual practices owed little to direct borrowings from the US. Canada was also the primary influence on the form taken by value-for-money auditing in other Westminster countries. It is suggested here that the decision by Canada in the early 1960s to recruit auditors-general from the private sector accelerated the transfer of value-for-money auditing to the public sector as did the admiration of Canadian auditors-general for the work of the GAO, even though they were constitutionally constrained in the extent of their borrowings.