Multiple sclerosis sufferers and their carers have handed in a thousand-name petition and letter to 10 Downing Street, urging the Prime Minister to support their call for a special drug to be financed on the national health.

The drug beta-interferon, which MS sufferers claim helps them fight the symptoms, could be withdrawn.

Among the banner waving demonstrators who first gathered outside the Houses of Parliament as Tony Blair entered for Question Time on Wednesday afternoon, was 37 year-old Andrew Samuels of Keighley, who has been denied the drug.

Leading the group, who later travelled down to Downing Street, was his father, David Samuels, of Oxenhope, chairman of the Multiple Sclerosis Support group. Members from throughout the country had gathered for the demonstration.

He said: "The letter asked the Prime Minister whether New Labour wanted to kill people rather then cure them. "It told him that it was unfair that people who were victims of chance, like MS sufferers, were not treated in the same way as people who become ill by smoking and drinking."

Andrew Samuels, a trained engineer, has not been able to work for two years because his disease is getting worse and he now has to use a wheelchair.

He has been refused the drug on the NHS - said to cost £10,000 a year - because his consultant believes it is not financially viable as a treatment for his progressive MS.

The National Institute for Clinical Excellence, which evaluates the effectiveness and value-for-money of new drugs, said it had made a provisional decision that beta interferon should not be prescribed on the NHS. However, MS sufferers already on the drug will still receive it.

NICE have said the ruling was only provisional and that the final decision would not be made until the end of July, following consultations with parent groups and drug companies. Bradford Health Authority has an interim policy in which patients with MS are given the drug if a specialist neurologist recommends it.