It is a peculiarity of our Constitution that the principles governing the formation and working of the Cabinet and its relations with Parliament can be stated with hardly any reference to the law. The law places no limit on the powers of Parliament and is not concerned with the process by which the Cabinet operates. When, however, the actual work of governing is considered, law and practice intermingle. The absence of a written constitution provides in this field not a complete absence of legal control, as in other fields, but a far more complex system of legal rules than is common in most systems of government. The Stuart conflict between King and Parliament left no reserve powers to the Government save the narrow royal prerogative and that supreme reserve power which is derived from the political control of Parliament. Stacks of statutes have added powers to Government departments. They have, however, provided detailed rules for specific purposes. There is no general power to govern.

The organisation and working of the Administration are thus closely regulated by law. Nor is that law built up on any consistent principles. It has been expanded to meet needs as they arose and modified as the pressure of experience demanded modification. There is no single legal entity called ‘the Administration’; there is no single and comprehensive constitutional provision governing administrative action; there is no general enabling provision granting administrative power.