Video report by ITV's Jon Hill
A couple from Barnsley whose twin sons suffer potentially life-threatening seizures have demanded the government free a logjam has denied them what could be a vital treatment for the last three years.Levi and Lucas Atwal-Brice, who are 15-years-old, both have epilepsy and autism, but only one of the boys has been given a cannabis-based medicine to ease his condition.
Their parents want access to a more potent form of the treatment.
But only three children in the country have received that drug on the NHS.
Today campaigners took their fight to Downing Street. Campaign group End Our Pain said families were being left thousands of pounds out of pocket after paying for private prescriptions - despite a change in the law three years ago allowing certain patients to access treatment through the NHS.
The Department of Health and Social Care says licensed cannabis-based medicines are funded by the NHS where there is "clear evidence of their quality, safety and effectiveness".
They said: “Our sympathies are with all patients and families dealing with rare and hard to treat conditions. The government has already changed the law to allow specialist doctors to prescribe cannabis-based products, where clinically appropriate and in the best interests of patients."