The treatment was a temporary boon for Lesley Friend, 57, who has had MS for 20 years. She found out yesterday she had taken the cannabis extract, but even on the trial was convinced it was not just the extra attention that was making her feel better.

"My legs felt an awful lot lighter, normally they feel like tree trunks and feel like I am walking through mud. With this, it was a bit like going back to my old self. I couldn't walk any further or run, but it is such a crime we are not allowed to have it [a cannabis treatment] now. It is depressing, knowing it helps."

Mrs Friend, from Devon, said: "It is a priority to get it to MS patients who want it, in the hope of even a slight improvement in a disease where there is no hope, no cure."

But there was disappointment for Lindsey Blatchford, 53, from Plymouth, who thought there was slight improvement at first when she took capsules she now knows had THC, the active ingredient in cannabis.

"It seemed to have some effect with pain in the beginning but it did not seem I was on a strong enough amount. It didn't last. It wore off. It didn't make such a difference as I thought it would."

She had never smoked cannabis and had no regrets being on the trial. "There was nothing else on offer to relieve me of any symptoms. I hope this will be legalised anyway for MS and I shall jump on the bandwagon."

But other patients she had met on the trial had benefited substantially. "There was a lady who at the beginning I could not understand she said, but within a few weeks she was talking quite normally," she added.