Hundreds of patients with a rare lung disorder could die and a Scottish centre of excellence in treating the condition could be threatened as a result of a decision by the medicines regulator for England and Wales, according to campaigners.

The National Institute for Clinical Excellence (Nice) is currently consulting on draft guidance for the rare lung disorder Pulmonary Hypertension.

In sufferers, a narrowing of blood vessels in the lungs leads to high blood pressure, putting strain on the heart.

Despite the fact that a cheaper generic alternative was licensed last week for use in the United States, Nice has judged that the class of drugs used by doctors for the sickest patients - prostacyclins - is not cost effective.

Edinburgh sheriff Graeme Warner, who is currently treated with prostacyclins for the condition, told The Herald it would be immoral' to deny the drug to future patients.

Professor Andrew Peacock, director of the Scottish Pulmonary Vascular Unit, said it was remarkable to tell doctors they could not prescribe a drug they know will help.

"When I talk to my European and American colleagues about this, they are absolutely amazed," he said.