Mrs Appleby told the BBC that cannabis oil had changed her daughter’s life, but she could not get a prescription from the NHS.

She said: “It’s absolutely disgusting that it’s been six years and we’re still in this position.”

She said she was paying for the drug through private healthcare and added: “I had to work so hard to keep raising money for the cannabis oil.”

In Brighton, Ryan Gillam, 31, has been living with sciatica and migraines for more than ten years.

He said he found traditional treatment methods had negatively affected his mental health and found medicinal cannabis significantly improved his condition with no side effects – but cost £500 every month.

“I would like it to be available on the NHS or for them to pay for part of it,” he said.

“It means I’m able to do everyday activities.”

A BBC investigation last year found that fewer than five people were prescribed medical cannabis by NHS England.