GPs in Bucks are being urged to limit men who need Viagra to just two tablets a month, in a bid to save NHS cash.

This is despite national guidance saying there "appears to be no clinical reason to restrict the number of tablets" prescribed to an individual.

Erectile dysfunction drugs on the NHS are already restricted to people suffering from conditions such as diabetes, prostate cancer and multiple sclerosis.

But now the South Central Priorities Committee, which makes rationing decisions for Buckinghamshire, Oxfordshire and other southern counties, has told doctors there should be a twice-monthly limit on erectile dysfunction drugs such as sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis).

Documents say the committee "has considered the evidence of clinical and cost-effectiveness, and the financial impact on the health economy of treatment for erectile dysfunction".

The average frequency of sexual intercourse in the 40 to 60 age range is thought to be about once a week.

The findings were uncovered by medical magazine, Pulse.

Editor Richard Hoey said: "Limiting patients to drugs like Viagra just twice a month is to treat sex like an unnecessary luxury, and completely fails to recognise the degree of anguish it can cause some men with erectile dysfunction."

A spokesperson for the NHS Buckinghamshire and Oxfordshire Cluster said: "Any decision made by the PCT cannot prohibit prescribing, but will form a recommendation to GPs."