Media playback is unsupported on your device Media caption Craig Williams and Rachel Rankmore say they are desperate for Bailey to get medical cannabis

"We so desperately want the medicinal cannabis. It could alleviate some of his pain."

It has been the plea by the parents of 16-year-old Bailey Williams, from Cardiff, who has severe epilepsy.

But Rachel Rankmore and Craig Williams said their son's consultant would not apply for the cannabis-based drugs on his behalf.

Cardiff and Vale University Health board said: "We always act in the best interests of patients."

The UK home secretary said specialist doctors could prescribe cannabis-based medicines legally from the autumn and until then, consultants can apply to an expert panel.

It followed a review into medicinal cannabis launched by the home secretary following an outcry over Billy Caldwell and Alfie Dingley being denied access to cannabis oil.

Bailey's family asked his consultant to apply to the panel but were turned down.

A spokeswoman said the health board would welcome the chance to speak to the family about Bailey's treatment.

Media playback is unsupported on your device Media caption Cannabis-derived medicines: What you need to know

Mr Williams said: "He could be the kid you see on TV riding a bike, or out the front with his mates but he's not.

"He's giving up and we're losing that lovely spirit he's got. He's fought for 14-and-a-half years and he's fought really hard. We've always said to him 'don't give up'. We're not giving up."

Bailey started having seizures when he was two and they became more frequent as he got older. He was diagnosed with a rare form of epilepsy, called Lennox-Gastaut Syndrome

He takes six different types of medication to control them.

"It became every day, twice a day, three times, four times. At one point there was activity every 2.5 seconds," said Bailey's father.

"We'd gone from watching a bundle of joy full of life, to someone who'd just sit on a settee, doing nothing. He couldn't even interact with the TV programme

Bailey's parents previously gave their son the legal cannabinoid CBD - costing £290 per bottle - and said it improved his quality of life.

Image copyright Family photo Image caption Bailey Williams can have multiple seizures every day

Cannabis is classed as a schedule 1 drug, meaning it is judged to have no therapeutic value.

The Home Office decision should put certain cannabis-derived products into schedule 2, with a potential medical use.

Director of campaign group End Our Pain, Peter Carroll, said a "massive cultural change" was needed in how the medical profession is briefed and trained about medical cannabis.

He added: "I've got families who are told by the local trust that they won't put an application forward because there's no policy on it.

"I've got neurologists telling patients who they've known for many years that it's just a passing trend, a passing fad.

"This is not entering into the spirit of the big bold announcement made by the home secretary and we're determined, on behalf of these families, to fight on their behalf and get a solution."

The UK Government said: "We completely sympathise with the families who have been facing desperate situations as they try to find treatment.

"Any proposed course of treatment with cannabis-based medicine must be clinically led."

The Welsh Government said, subject to the necessary legislation being approved by the UK Parliament, cannabis-derived medicine would be available for clinicians in Wales to prescribe.

"We need to work together and get this sorted because we want our children's lives back," said Ms Rankmore.