Earlier quoted context omitted.
> Could you please give me your real name "celticninja", your phone number, your address, your NI number The police can and will request this information from you, digital ID or not. If you have actual beef with digital ID, present it.
They can certainly ask, but at the moment can they jail you simply for not answering?
They'll invoke one of the more ambiguous sections, it's usually the anti-terrorism one, but sometimes is the anti-drugs one (i can't remember the numbers), and they'll detain then arrest you and haul you to the police station.
You can complain later, and maybe get some pounds out of it, but make no mistake: if the uk police wants you identified, they will identify you.