GPonline reported last week on the decline in overall GP numbers - the total number of full-time equivalent GPs has dropped by around 1,300 in the past two years alone.
But another major feature of the threat facing the GP workforce is the growing proportion of doctors who are close to retirement age - the so-called 'retirement timebomb'. Click on the interactive map below to explore how the ageing workforce affects different areas.
Map: which CCGs have most GPs over 55?
In parts of England, close to half of the full-time equivalent workforce is aged over 55, and in 20 CCGs more than a third of GPs are aged over 55. With the average GP retirement age at 59, many could soon reduce their work commitments or leave the workforce altogether.