Mrs Moses will have to wait 18 months for a hip replacement

Plaid Cymru AM Ieuan Wyn Jones received a letter from a surgeon at a hospital near Oswestry after making inquiries for a constituent.

Orthopaedic surgeon Patrick Gregson said he could not operate on Elizabeth Moses from Menai Bridge any sooner because of the rule.

An assembly government spokeswoman said such a policy was "simply not true".

The Robert Jones and Agnes Hunt Orthopaedic Hospital in Gobowen also denied the claim, saying no Welsh patients were waiting beyond 18 months and the average wait for people from Wales was 13-15 months.

Mrs Moses has osteoarthritis and needs to have her left hip replaced. She has already had her right hip replaced.

I can't walk, I can't sit down. Sitting is more painful than actually walking Elizabeth Moses

She told BBC Radio Wales she was unable to sit down without suffering severe pain, but was told in August she would be on the waiting list for 18 months.

"I can't walk, I can't sit down. Sitting is more painful than actually walking.

"When I'm standing, I can stand more on one leg and hang the other one."

Mrs Moses said she did not understand the economics behind delaying her operation so long.

In a humane society she would have her total hip replacement performed within a few months of going on the waiting list Patrick Gregson

She said medication she was taking until she could have the operation would cost �1,000 over 18 months and they would still have to operate after that.

In Mr Gregson's reply to Mr Jones about her operation, he wrote: "Mrs Moses is very disabled and distressed by her osteoarthritic hip and in a humane society would have her total hip replacement performed within a few months of going on the waiting list.

"Unfortunately, due to government targets and lack of investment in the health service by the Welsh assembly, I am not allowed to operate on patients from Wales who have not waited 18 months.

"The Welsh purchasers have decided they do not want their patients to be admitted within 18 months."

Mr Jones said: "This reply reveals a scandal in the Welsh NHS where there is a deliberate policy of keeping patients waiting more than 18 months for treatment at Gobowen.

Administrators

"We have long suspected that the Welsh Assembly government have tried to hide this from us, but Mr Gregson's letter has laid bare (First Minister) Rhodri Morgan and (health minister) Jane Hutt's duplicity.

"I find it almost incredible that the Welsh health minister is perfectly happy with a situation where Welsh patients are kept in severe pain for more than 18 months without treatment."

First Minister Rhodri Morgan responded that he interpreted Mr Gregson's letter as a "cri de coeur" (cry from the heart) to the hospital's administrators.

He said: "He is not happy with what is happening in the hospital. I read it as he is just as unhappy with regard to his English patients.

"Everyone at Gobowen is quite clear that 18 months is a maximum," he said.

"We are perfectly clear that it's the clinical priority which should determine when they are treated."

An assembly spokeswoman added: "The story of a deliberate policy to keep patients waiting more than 18 months for treatment is simply not true.