Sessional requirements in respect of appropriation

34.38The constitutional importance of the principle of appropriation was emphasised earlier (see paras 33.7–33.11 ). In accordance with the principle, there was formerly a requirement that all legislative authorisation for expenditure through a Supply bill was required to take place in the same session as that in which the founding resolutions were agreed. It remains the case that amounts authorised by Supply resolutions relating to Estimates, Supplementary Estimates and Excess Votes must be appropriated in the same session as that in which they are passed, so that all such authorisations would be nullified in the absence of an Appropriation Act. However, resolutions relating to Votes on Account passed in one session (usually in March) have full effect even if not appropriated in the same session, and the same applies to votes setting maximum numbers for defence services.1