Available directories for UK businesses (in addition to Google Places) are as follows:

UK Big 6 Additional Local Business Directories
Yahoo! Local Brown Book
Bing Local Applegate
Local Data Search U Find US
Market Location Scoot
Info Serve Trusted Places
Qype B View
  UK Cities
Local Sites/Industry Specific Sites Smile Local
Business Directory UK Thomas on Local
City Local Tipped
The Beso of UK Touch Local
Free Index Yell
  Square Meal
  Fancy a Pint
  Hotel Guide
  London Online
  All In London
  London Town
  Time Out
  Viva Street
  City Visitor
  Spoon Fed
  View London
  Visit London