In liberal democracies, parliaments exercise oversight over the security sector, including intelligence services. This is usually conducted by a standing select committee with cross-party representation. Such committees normally take one of two forms: specialized committees dealing exclusively with oversight of intelligence, or committees with broader mandates, responsible for oversight of the whole security sector.

Given that intelligence services operate in clandestine fashion, great care must be taken to address concerns regarding the protection of their assets, methods, operations, and other classified information. Accordingly, the effectiveness of the parliamentary oversight committees is dependent on their ability to access relevant classified information. Individuals whose work requires access to classified information may be required to undergo a process of vetting.

Concerns remain as to whether such vetting procedures are equally applicable to members of parliaments, and if so, which body should be responsible conducting them. This is particularly the case for countries in which intelligence services are themselves responsible for the vetting process, with some arguing that this may challenge effective parliamentary oversight.

To this end, this Thematic Brief outlines two approaches to the vetting of members of parliament. For each, the general standards and procedures are detailed with reference to case studies; with the limitations of each approach, as well as possible strategies to overcome these, also presented. The Brief concludes by identifying recommendations based on best practice and internationally recognized norms, which underscores that regardless of the approach taken, suitable mitigating policies should be enacted.