So Tony Blair’s government is mounting a clumsy attack on graffiti. “The natural liberal response to this is to defend the richness and wildness of graffiti, the layers of rotting posters, scrawled secret language and spray-can calligraphy that makes dull walls speak hidden dreams in fat lurid lettering. To deny any connection between graffiti and art is not tenable, given the fascination it has exerted on serious painters since the second world war. In the 1980s the intellectualism of Twombly and Dubuffet spawned a far coarser appropriation of street painting by art dealers who fell over themselves to represent the graffitists Keith Haring and Jean-Michel Basquiat. And that’s when it all went wrong for graffiti.”