I think this treatment can make a very big difference to a patient's life

Prof Gabriel Panayi

They are regarded as the only effective treatment for patients with severe rheumatoid arthritis who have failed conventional treatments. The treatment is widely used in the US, Canada and elsewhere in Europe.

However, anti-TNFs are costly and the National Institute for Clinical Excellence (Nice) will decide next year if two of these drugs, Etancercept and Infliximab, should be available on the NHS. The drugs can cost as much as �800 per patient per month.

In the meantime, patients are suffering from a postcode prescribing lottery depending on where they live.

Wide variations

The survey reveals wide variations across the UK, across regions, within health authorities and even within trusts.

Consultants in just one in six trusts said they had adequate funding to pay for the treatment.

Gabriel Panayi, professor of rheumatology at King's College London, said the drugs should be available to those patients who need them.

Prof Panayi says the drugs can make a big difference

"I think this treatment can make a very big difference to a patient's life. In the people who have received it we have seen a terrific response."

Nice will decide whether the drug will be a cost-effective treatment on the NHS. However, Prof Panayi has criticised this approach.

"One of the problems with referring drugs to Nice is this question of cost effectiveness. With RA, which is a severe disease, we are faced with a situation where treatment of it today with existing drugs is relatively cheap. That is a problem when you start looking at cost effectiveness.

"But we know that 80% of patients within five years are not able to work so the cost to you and me as taxpayers in terms of unemployment, welfare benefits other hidden costs, carers taking time of work is probably at least �1.5bn a year," he told BBC News.

"I think it is short-sighted to simply look at the medical costs. We should look at the total costs, which are enormous. Why should people be out of work when perhaps better treatments could allow them to stay at work?"

A spokesperson for the Department of Health said: "We can't comment in detail while the NICE appraisal process is underway. But we're determined to end postcode prescribing.

"Patients should have access to the latest, effective drugs and treatments and that's exactly why NICE is looking at these drugs."

Rheumatoid arthritis is caused by inflammation of the tissues surrounding joints, leading to their progressive deterioration.

It extreme cases it can even kill patients by causing major organ failure.

An estimated 370,000 adults are affected by the condition in the UK.