Medicinal cannabis oil will be available on prescription from next month, the Home Secretary said on October 11.
From November 1, UK laws will change to allow cannabis-based products for medicinal use to be prescribed in England, Scotland and Wales, according to a written statement from Sajid Javid.
The dramatic change to policy follows several high profile cases of patients being denied products containing THC, the psychoactive compound that makes users 'high', came to light.
Epileptic boy Billy Caldwell was even banned from taking cannabis oil that was prescribed to him abroad.
He was given back the medicine after a high profile campaign spearheaded by his mother forced Mr Javid to grant a 20-day emergency licence for its use.
Billy Caldwell's mother Charlotte (pictured together) had seven bottles of cannabis oil confiscated at Heathrow Airport customs, prompting a row over cannabis oil
The Home Secretary has insisted today's change is not the first step towards the broader legalisation of cannabis.
Mr Javid announced on 19 June that the Misuse of Drugs Regulations act of 2001 was being reviewed in a two-part investigation to allow for the prescription of medicinal-cannabis products.
In the first part of the review, the chief medical advisor, Professor Dame Sally Davies, concluded there was evidence that medicinal cannabis has therapeutic benefits.
The second part, carried out by the Advisory Council on the Misuse of Drugs (ACMD), recommended drugs that meet a clear definition of a cannabis-derived medicinal products should be placed in Schedule 2 of the Misuse of Drugs Regulations 2001.
Cannabis was previously considered Schedule 1. Drugs in this class are thought to have no medicinal value and therefore cannot be legally possessed or prescribed.
Schedule 2 drugs, such as ketamine, are those that can be prescribed and supplied by doctors and pharmacists. They can also be legally possessed by anyone with a prescription.
In 2017, when Alfie was just five years old, the family moved to the Netherlands so he could take part in a cannabis oil trial.
'Before we went we got the blessing of Alfie's paediatrician and our local MP as we wanted to do everything openly,' Mrs Deacon said.
'We're aware that some people don't do that but we felt we shouldn't have to break the law to keep our son alive.
'The doctors in the Netherlands started treating him with cannabis oil, which is administered as an oil under his tongue that is then absorbed by his bloodstream.
'He didn't respond to start with as it takes time for the cannabis oil to build up in the body. I was extremely worried that it wasn't going to work.'
But just five weeks into the treatment, Alfie's family began to notice a remarkable change.
'He stopped having seizures. He became happier. And his cognitive development started to improve,' Mrs Deacon said.
'He has learning and speech delay, and had regressed as a result of his epilepsy and the steroids, and only managing to do three weeks at school.
'Cannabis oil has been a miracle for Alfie.'
After five months of treatment in the Netherlands, Alfie's family felt they had all the evidence they needed to campaign for medicinal cannabis oil to be made legal in the UK.
'We returned and obviously had to take Alfie off cannabis oil. He became very unwell again,' she said.
'A lot of people got in touch via our Facebook page Alfie's Hope - and those messages kept me going.
'Our MP arranged a meeting with the Home Office in the March and we took a petition bearing 370,000 signatures to Downing Street where we met the Prime Minister Theresa May.
'We told her about Alfie and she said she would do all she could to help. We were pleased.'
Although backed by a lot of support, the family still faced challenges getting their voice heard.
'But then it seemed like we were faced with a pharmaceutical trial application - we weren't a big national drugs company we were just a family with a small child who desperately needed medication,' Mrs Deacon said.
'It became apparent by June that we weren't getting anywhere so I did an interview on Radio 4 where I talked about my meeting with Theresa May and how I felt I'd been let down.
'Soon after, home secretary Sajid Javid got in touch to say they were issuing Alfie with a licence and reviewing cannabis as a medication.
'We were delighted. Our doctor is now free to prescribe this medication for our son without worry of his career or any of his colleagues saying that he shouldn't.
'And, as soon as Alfie had cannabis oil back in his system, he started to do really well again.'
With his epilepsy now under control, Alfie can even ride a bike.
'It's absolutely amazing that he can do that,' Mrs Deacon said.
'We had tried to help him learn to ride his bike but he just sat there and pedalled backwards which is sad because every little boy should be able to ride a bike.
'He's now learnt how to ride a bike, which has been brilliant.
'His sister Annie is four now and has started school. His condition is not impacting on her now the way it was.'
Now his epilepsy is under control, Alfie is thriving. The youngster attends school every day and has learnt to ride a bike, which his mother says is 'absolutely amazing'
And the whole family have benefited, with Alfie no longer hitting his sister Annie (pictured being held by their father Drew) during his psychotic episodes
Mrs Deacon is speaking out ahead of an Epilepsy Action event on Thursday to raise awareness of the benefits of medicinal cannabis oil.
'Cannabis oil will be prescribable from November 1 2018,' she said.
'However, a lot more needs to be done so that doctors understand the medical uses of it.
'I feel people should have the right to use it but some doctors don't feel it's safe because it's not been tested in the same way as other drugs.
'But it's probably one of the safest medicines you can use.
'We produce cannabinoids in our bodies and this is the closest thing to our own make up.'
The body's cannabinoid receptors are part of the endocannabinoid system, which is involved in physiological processes including appetite, pain-sensation, mood and memory.
'Cannabis oil can be used for so many illnesses,' Mrs Deacon added.
'Doctors are used to having just one drug for one use but if your body is depleted in cannabinoids then cannabis oil can help the body neurologically with conditions like MS and Parkinsons.
'It can also help the auto-immune system and it's amazing for helping with pain relief, especially in conditions such as arthritis.
'It's good for lots of different symptoms so I believe it could help lots of people.
'It makes me very upset because it is could be so simple. But we're fighting 50 years of people believing cannabis is bad.
'We need to talk about it medically not recreationally. We need to raise awareness of it.'
WHAT IS CBD OIL AND IS IT LEGAL IN THE UK?
Government advisers made it legal to buy CBD supplements in 2016
CBD oil is a legal cannabinoid that can be sold in the UK.
CBD contains less than 0.2 per cent of the psychoactive substance THC.
Although the oil has been thought to have some medicinal properties, including relieving inflammation, pain and anxiety, there is no conclusive science.
Suppliers in England and Wales have to obtain a licence to sell CBD as a medicine.
Manufacturers are able to avoid the strict regulation by selling it as a food supplement - ignoring the lengthy process of gaining a medicinal licence.
CBD products comes in many forms, the most popular being an oil - which users spray under their tongue - or gel tablets which melt slowly in the mouth.
Government advisers at the MHRA found that CBD has a ‘restoring, correcting or modifying’ effect on humans.
Cannabis oil, which is different to CBD oil because it contains THC - the compound that gives users a 'high' - is illegal under UK laws.
Billy Caldwell, from Castlederg, Northern Ireland, made headlines last April when he became the first Briton to be prescribed it on the NHS.
Cannabis oil, which reportedly has no side effects, influences the release and uptake of ‘feel good’ chemicals such as dopamine and serotonin.