This paper analyses an important Canadian experiment in the legislative scrutiny of political appointments by the executive. Since 1991, the Ontario Legislature’s Standing Committee on Government Agencies has routinely interviewed cabinet appointments to semi-independent agencies, which are a major policy instrument at both federal and provincial levels in Canada. The Committee was assigned this task on the assumption that partisan Members could agree on criteria for questioning witnesses about their qualifications, and that the government would be willing to withdraw candidates exposed as inadequate. At the same time, the governing party retained the discretion to make partisan appointments. An examination of how the Committee conducts interviews reveals a tension between the Members’ role in holding the executive accountable, and their identities as partisan politicians. In large part, the Committee has become a forum for debates on the appropriate limits to patronage in appointments to public bodies. A perennial theme in the analysis of the Westminster system of parliamentary democracy is the necessity for institutional reform to redress the imbalance of power between the executive and legislature. Reform is needed to ensure that the legislature can properly perform the scrutiny and oversight functions assigned to it under the norms of the Westminster model. A popular focus of attention is the expansion of legislative committee systems, which are regarded as an essential element in an effective scrutiny regime. In many jurisdictions committees have been added and re-structured in order to strengthen the legislature’s capacity to debate ever increasing volumes of government business, enhance the supervision of government departments, and to enable legislators to initiate their own investigations into public policy. For students of the Westminster model, effective legislative supervision must be extended to arm’s length agencies, boards or commissions (ABCs) or quangos in those regimes where these play a significant role in governance, notable examples being Canada and Britain. ABCs are an important policy instrument at both levels of the Canadian