Shortcomings in the system of registering deaths in England and Wales are introducing delays in the official response to disease epidemics and could even be causing additional deaths, statisticians have warned.

The Royal Statistical Society and several charities have written to Prime Minister David Cameron to urge him to scrap a rule that means deaths are not officially recorded until inquests reach a verdict on their cause - a process which can take months or even years.

They say that switching to the Scottish system of registering all deaths within eight days could improve the way the authorities respond to epidemics and monitor the impact of public health policies.

The RSS has been campaigning for a change in the law for five years.

Spokeswoman Sheila Bird told the BBC Radio 4's Today programme: "The problem in England and Wales is that deaths which are referred to the coroner are not registered until the verdict has determined cause of death, which can be months or years later, whereas in Scotland, without exception, all deaths must be registered within eight days of death having been ascertained.

"This means that we know promptly and properly who has died and when. We will know the final cause of death at a somewhat later date in Scotland, as in England and Wales, but the benefit for the statistical system in Scotland is that the national registry knows for whom it lacks a cause of death and can chase to find out and can therefore minimise registration delays."

Asked if the problem could be causing additional fatalities, Prof Bird said: "Potentially, because we delay discoveries."

She added: "F or getting a grip on new epidemics - the next pandemic influenza - we need to know who has died when and we need that information in real time, not in delayed time."

Delays in death registration made it more difficult for researchers to conduct studies which follow a group of participants through their lives and more difficult for the authorities to understand the impact of their policies, said Prof Bird.

"For example, if a series of criminal convictions has ceased, is that due to rehabilitation of the offender or because he has died? We don't know unless we know promptly about fact of death," she said.

Studies into issues like the prevalence of opiate-related deaths following release from prison or the impact of the financial crisis on suicides have been affected by the delays.

"What we are calling for is a correction to the statistical system so that it counts all deaths promptly, irrespective of whether an inquest is required or not," said Prof Bird.

"We need to register fact of death, as in Scotland, within eight days. In England and Wales, legislation is needed to uncouple the registration of fact of death - which should always be prompt - from the later registration of the verdict on cause of death."