Popping champagne, skulking off to smoke a spliff and pledging to become a life-long Labour voter. Anyone concerned about criminal justice in Britain will find the well-documented glee of the 1,700 prisoners given early release around the country this week galling indeed. As domestic abusers and career criminals walk free, many will have been struck by the contrast with the government’s response to last month’s riots, bringing to mind that most irresistible of epithets: ‘two-tier Keir’.