The idea is being brought to the annual conference of the British Medical Association in Bournemouth.
The proposal says that the “black alert” system for GPs would be similar to those used in hospitals.
This would mean that patients would have to be diverted elsewhere if their local practice could not offer urgent appointments.
The idea has been put forward by the BMA’s eastern region.
Dr Peter Holden, from Matlock, who is to propose the motion, told The Times today: a GP from Matlock in Derbyshire, who will propose the motion, said: “It seems as if one half of the health service can say ‘we have done everything we can cope with’ and the other half is expected to sweep up all the work.
“There has to be a limit on what you can do in a day — what it is reasonable to ask a human being to do in a day. It is not about money, it is about patient safety.”
The idea was backed by Royal College of GPs chair Professor Helen Stokes-Lampard.
She said: “We certainly need some sort of warning signal to sound in general practice when things are getting too much.”