I don't know Dominic Cummings well and I can only speculate what influence he did or didn't have on the recent Government reshuffle. I am always a bit sceptical of the belief in all-powerful Svengali figures pulling the strings of puppet politicians. Good headlines, but seldom sound analysis.

That said, the Prime Minister's chief adviser is clearly a man of great influence and strong views on a remarkable range of topics – apart, as far as I can see, on local government.