I'm not really proposing a new law - just the application of existing laws about manslaughter to people who, historically, do a lot of it. Just because there are a lot of prime ministers that have fallen well short of any reasonable standard when it came to decisions that cost lives does not mean that we should continue to give governments carte blanche.

What you are describing is not a dysfunctional idea, but rather a dysfunctional system where there is no accountability. Boris Johnson can break the rules on donations (for example), pick an investigator for an 'independent investigation', and nobody will even mention the fact that it's a complete farce, because all the journalists are afraid of losing access.