Who has the power to authorise perjury?

One of the most striking things about the last few decades is that relatively low-ranking elements of the state apparatus have arrogated power to themselves without any legal or legislative basis, and that this has been calmly accepted by the public at large.

Because these seizures of power are technically illegal, they can be challenged in the courts, and occasionally are. See for instance Neil Herron's campaign against imposition of arbitrary parking rules by local councils.

While the courts can, and technically should, rule in favour of eccentrics such as Herron, they sometimes exhibit reluctance to contradict the common assumptions of society, which are that someone who works for the council or the police or a government department can do whatever they decide within the area relevant to their job.

Because it is so accepted, it is not easy to spot, and only becomes really obvious when they overreach. What is interesting about the police decision to "authorize" an undercover officer to give false personal and identity details under oath in a criminal prosecution is not whether they will actually get away with it this time (I assume they won't), but that they ever imagined they could.

The same effect was evident with the MP expenses affair: I quoted at length Nadine Dorries' insistence that a group of party whips and civil servants had encouraged MPs to make false expenses claims, and that that actually made it OK.

A more significant example is the Foot and Mouth cull back in 2001, in which, it is widely argued, the culling of healthy cattle was done without any legal authority.

At this stage in the post, I should turn these observations into a neat argument in favour of whatever broad political position I am in favour of at the moment (formalism, monarchy, etc.) I suppose I just about could manage it: lines of authority are unclear, nobody ultimately admits to being responsible for anything, so people on the spot feel obliged to just assume responsibility, blah, blah, blah. If I thought about it and worked on it for a while, I might really come to take it seriously as an argument, but right now it feels a little dishonest, so I'd rather just put the whole thing forward as an observation and a point for further consideration.