Answer:
The 33 divisions of the London Urban Area - City of London (officially not a borough), City of Westminster, Kensington and Chelsea, Hammersmith and Fulham, Wandsworth, Lambeth, Southwark, Tower Hamlets, Hackney, Islington, Cambden, Brent, Ealing, Hounslow, Richmond upon Thames, Kingston upon Thames, Merton, Sutton, Croydon, Bromley, Lewisham, Greenwich, Bexley, Havering, Barking and Dagenham, Redbridge, Newham, Waltham Forest, Haringey, Enfield, Barnet, Harrow and Hillingdon.