Advisers should report doctors who do not provide GP reports within 21 days to the British Medical Association, according to the Association of British Insurers.
In some life cover and critical-illness cases, insurers require a medical examination or GP report before they put the customer on risk.
One adviser raised concerns about the length of time that GPs are taking to return the requested reports.
He said: “I find that I am fighting a battle with the GP, the insurer is fighting a battle with the GP, and the GP is saying ’I have more important things to do, so don’t bother me’.”
ABI assistant director of health and protection Nick Kirwan said: “The ABI has an agreement with the BMA on the supply of information to the insurance industry.
“BMA guidance says that GPs should provide reports within 21 days, and if GPs do not do this they are in breach of this guidance.
“Advisers should report these cases to the BMA. If the BMA does not hear about these cases, it will not be aware there is a problem. Sooner or later, somebody is going to suffer a critical illness and it will turn out that they are not on risk because of a doctor’s negligence.”
The BMA was unavailable for comment on the issue.