Earlier this year parents from 10 families headed to Westminster to deliver a giant, £230,000 invoice to the government.

The amount reflected how much they had spent on buying vital cannabis medicine for their children.

Among them was Karen Gray, whose son Murray (pictured), seven, has a rare form of epilepsy which she has treated using cannabis oil.

This was her second trip from Edinburgh to the capital with the campaign group End Our Pain.

The first saw health secretary Matt Hancock face a grilling from her and other parents desperate to access cannabis medicine on the NHS.

He acknowledged the struggles many families are undergoing in accessing medicinal cannabis but, says Karen: “He’s done absolutely nothing since. He said he knows that we can’t wait several months and said he would do something to help us. This was back in April.”

Karen, second from right, with fellow cannabis medicine campaigners in London

Karen, who is currently spending £1300 per month on cannabis oil, continues to protest.

She recently told the press that she and other mothers planned to carry out a hunger strike outside Downing Street; as families remain locked out of cannabis medicine prescriptions, despite them being legal in the UK since November 2018. Theses plans remain on hold until after the general election.

Karen’s motivation is far from merely financial; she wants other families to benefit from the type of remarkable results seen in her son, which she firmly attributes to cannabis oil.

Murray seemed perfectly healthy as a baby, then at age two doctors picked up a delay in his speech development due to a ‘micro deletion’ of a chromosome.

Epilepsy was thought to be a related problem; but initially manifested as only one seizure per year. This then doubled – and doubled again – then increased with worrying speed.

In December 2017, a then-five-year-old Murray had 12 seizures. He was diagnosed with Doose Syndrome, an epileptic condition in which seizures can be frequent and involve the abrupt loss of muscle control, causing children to fall to the ground, often resulting in injury.

“He had just started school in the August, and by December had learned to write his name. Then Doose arrived and by January he was having 12 seizures a day.

“He was put on anti-epileptic medication and we started seeing all types of seizures – absences, drops, myoclonic (brief, shock-like jerks of a muscle or muscle group). He was put on various medications and nothing worked.”

At its worst, Murray could have up to 600 seizures per day.

“The steroids made him put on two stone of weight in three months and he looked like a different person. His best friend at school didn’t even recognise him and was scared as he looked so different.

“He was also given ketamine as a rescue drug for a week but that didn’t work at all. He was just basically out of it.

“I thought ‘oh my God, they’re giving my five-year-old son horse tranquiliser’ but you just have to trust the doctors because he was in such a bad way.”

Other drugs came and went from Murray’s daily routine without having the desired effect.

Then Karen took inspiration from a fellow mother who had also struggled with the impact of epilepsy on her young son.

“I read the story of Hannah and little Alfie, and how his seizures were reduced with medical cannabis, and decided I needed to go to Holland to get some for Murray.”

Joining forces with two other mums of children with Doose Syndrome, she headed across the North Sea in search of a doctor’s prescription.

But mid-trip she received a call from Murray’s neurologist to say a trial of the CBD drug Epidiolex had been secured back in Scotland.

Although welcome news, it ultimately proved a false dawn in terms of giving Murray the normal childhood his mother craved. At the time, alongside his seizures, Murray also had a problem with red blood cell production and had to undergo several transfusions.

The seizures during the day stopped on Epidiolex, which was a massive breakthrough, while he still had some through the night. But he was also suffering chronic diarrhoea.

“I was getting calls from his school two or three times a day to go and change him, but it was a side-effect we were willing to put up with because at least he was able to get up and go to school for a few hours.”

Within months, the daytime seizures had gradually returned, culminating in a particularly bad attack while on holiday at Center Parcs.

“He was rushed to hospital in Edinburgh and it was truly awful. There was nothing they could do; his muscle tone went, his breathing went and he was basically lying in a bed getting tube fed in a vegetative state. I don’t even think he knew we were there.”

This time Karen did get a prescription for cannabis medicine from a Dutch doctor – not exactly with the full support of Murray’s doctors.

“They said if they knew about it they would have to report me on child protection grounds, which was fair enough. They also said they feared that I could be doing long-term damage because of the THC.

“But by this point I had done so much research and spoken to so many other parents that I knew that it was a tiny amount of THC that they gave to kids in places like Canada. I just knew that this was something I had to do. I had no choice.

“I brought it back and gave it to him behind the curtain at the hospital, as I didn’t want to get anyone else into trouble.”

At this time, age six, Murray had been brought out of an induced coma designed to “reset” his brain using the epilepsy drug phenobarbital.

“I started giving him the medicine (Bedrolite) and I could see he was getting better. We got discharged and went home again but within a week he went downhill again.

“After a brain scan, the neurologist said he was in a bad way. But Murray wasn’t being tube fed in a vegetative state, he was walking about the neurologist’s office.

“I was sure that the oil was working as nothing else could explain it.

“We started giving him Bedica (containing a low level of THC) twice a day and he just got better and better and better.

“He had one seizure a week, then one a fortnight.”

At the time of writing he has been seizure free for seven months.

“The neurologist said that the syndrome can come and go – it can be really bad and get better.

“But I don’t know anyone with Doose that has gone this long without anything. He also said it could be the oils that we were giving him, but that he just couldn’t help us with a prescription.

“He said even if he wrote one, it would get blocked at a higher level and also that he didn’t want to be the first to do so. The doctors are all scared to prescribe it as it’s going to come under their insurance and they just don’t want to take that risk.

“It’s really annoying because we can see what it’s doing for Murray. I don’t think it should even be up to one neurologist to write the prescription. They should come together and do it jointly for all the kids that need the oils.”

Medical bodies who have remained resistant to supporting doctors in prescribing cannabis often point to the need for more evidence.

“We’ve already had our trials and proven that this works. I think more trials will happen but they will take a long time.

“Epidiolex is a CBD isolate so you can do clinical trials on that. But with whole plant extract, there are so many cannabinoids that you can’t single them all out to do double blind placebo trials.

“I really want to see funding in place so that, if the NHS can’t write a prescription, there are funds so families can buy the medicine.”

The future prospect of an NHS prescription for Murray is uncertain.

In Scotland, says Karen, “there are GPs willing to write a prescription – and healthcare trusts that I have been told will not block it.

“Yet those GPs are not on the specialist register set up to manage medicinal cannabis access in Scotland. ”

In England, the challenge as Karen sees it, is more a case of the trusts blocking prescriptions from willing doctors.

Although a significant sum, the £15,600 per year cost of Murray’s medicine is a small price to pay for his newfound quality of life.

The seven-year-old is now attending mainstream school full time, and requires non of the cast of health professionals that used to be in his life.

“He’s had to redo everything because he basically lost a year and a half of his education but  he’s learning now, picking up the alphabet and learning to do new things.

“He loves playing with sand and Play Doh – lucky me! – and building train tracks, going climbing and going swimming. He had lost his confidence in the water but it’s building back up and he’s doing great.”