The prerogative has come up so often that I will deal with it now in substance. Prerogative powers, of course, developed at a time when the monarch was both a feudal lord and Head of State. That is the origin of prerogative powers, but they have changed over time, yielding where necessary to the demands of democratic accountability. There are plenty of examples, as the Secretary of State will know, in the courts of that change in accountability, but there is also the example of the prerogative power to commit troops in armed conflict. In theory, the Prime Minister and the Cabinet retain the constitutional right to decide when and where
to authorise action, but in practice Governments in recent times have ensured parliamentary debate and a vote.
Responding to the Chilcot report earlier this year, the then Prime Minister made the point during Prime Minister’s questions when he said:
“I think we have now got a set of arrangements and conventions that put the country in a stronger position. I think it is now a clear convention that we have a vote in this House, which of course we did on Iraq, before premeditated military action”.—[Official Report, 6 July 2016; Vol. 612, c. 881.]
A strong political convention modifying the prerogative has thus been set.