In the coming days, you’re going to hear a lot about Sir Keir Starmer’s first 100 days. There will be newspaper interviews to mark the moment when it arrives on Sunday, a trip to Scotland to convene his new council for the nations and regions and a big investment summit early next week. The PM will be all over the television trying to tell you how he’s changing this country, as the columns land — like this one — dissecting his performance to date.