London could face a potential "shortfall" in GPs as a "significant" number approach retirement age.
A report by think tank The King's Fund found the ratio of practice staff to GPs to be lower in London than in other parts of England.
Furthermore, some parts of the city have "relatively fewer" GPs per head of population, and almost 16% of GPs are over 60 years old.
Anna Dixon, director of policy at the think tank, said the report highlights the "significant number" of GPs coming up to retirement age.
She urged London practices to "urgently address" a potential shortfall in the number of GPs in the near future by changing the skill-mix in their surgeries.
It is claimed practice nurses and healthcare assistants could be given a "greater role" in London's GP surgeries to cope with the potential GP "shortfall".
"There is clearly a need to recruit GPs in London but given the likely challenges we will face in doing so in the short-term, there will also be a need to diversify the skill mix of practice staff in London, for example recruiting more practice nurses and healthcare assistants to work alongside GPs," she said.
Given the demands on general practice, Dixon argued "it is really important" that GPs are spending their time with patients who really need the more, expert, generalist knowledge.
"There are things that GPs do that could be better routinely managed by nurses," she said.
Dr Alison Hill, medical director for Londonwide LMCs, said London's general practices need more clinical time with patients. For this to be achieved, she agreed there needs to be a growth in the recruitment of GPs and practice nurses, but also called for better staff training and "essential" improvements to existing premises.