The �6.10 prescription charge is a tax at the moment, a stealth tax on people that are unwell

Dr Peter Outen

And 98% of GPs questioned said they advised members to buy cheaper over-the-counter drugs to avoid the �6.10 prescription charges.

Some GPs even admitted writing "proxy prescriptions" so other family members who didn't pay for their prescriptions could get them for relatives.

Anomalies in the current system mean that some people with chronic conditions such as diabetes are exempt from all charges whereas others with conditions like asthma have to pay.

Call for changes

Some women on hormone replacement therapy even have to pay twice for their treatment because they use two different sorts of drugs.

Dr Peter Outen, a GP in Brentwood, Essex, said the current system was a sham and he called for rapid changes.

"At the moment we've got an absolutely loopy system.

"I'm a fan of a bit more honesty. It's a con at the moment. The �6.10 prescription charge is a tax at the moment, a stealth tax on people that are unwell.

"I think that is invidious."

Dr George Rae, chairman of the British Medical Association's (BMA) GP prescribing committee and a GP in Whitley Bay, said this was an area of concern and called for changes.

"This has been felt a lot for the last decade."

In the light of its findings, Doctor has pledged to launch a campaign for a complete overhaul of the system and has said it will be targeting health ministers, MPs and GP organisations.

In an open letter to Health Secretary Alan Milburn, Phil Johnson the editor of Doctor called for an end to health inequalities.

"Nearly four years ago your party swept to power amid promises to eliminate inequalities in health provision to patients.

"But today, what is arguably the most unfair part of the NHS still remains - the prescription system.

"I hope you will agree that the time has come to look again at the system of prescription charges and exemptions - let's have a full and open debate."

A Department of Health spokesman said 85% of prescriptions were dispensed free of charge to exempt patients such as children and pensioners.

The cost of a prescription went up by just 10p last year, the lowest rate in 20 years.

He said: "The government is fully meeting its commitment to restrict the increase in prescription charges to no more than the rate of inflation."