The mother of a severely epileptic boy who had his cannabis medicine confiscated is hoping "common sense will prevail" as she waits on a Home Office decision on whether to permit the oil treatment.

Billy Caldwell, 12, was admitted to Chelsea and Westminster Hospital in London on Friday after his seizures intensified.

Speaking outside the hospital on Saturday, his mother Charlotte said: "Unfortunately, Billy had two more seizures overnight which has pushed him more into a crisis situation."

She added: "The Home Office, myself and my team have been working extremely hard throughout the night to make this happen, which is truly amazing, but there can only be one conclusion here: that my beautiful sweet little boy, who has a life-threatening form of epilepsy and one seizure can kill him, he needs his medicine back today."

"There's a lot of bureaucracy around this and we are working towards obviously Billy getting his medicine and it's just one step at a time but we are confident the Home Office is working with us and we are going to get this done."

Ms Caldwell has said the Home Office will be held accountable if Billy dies, calling its actions "beyond cruelty".

Keen to get back to her son's bedside, she said: "I am full of hope - this is my little boy's anti-epilepsy medication.

"I am hoping the common sense will prevail."

On Friday night the Home Office said it was in contact with Billy's medical team and would "carefully consider what options are available" if they advise a particular type of treatment is urgently required.

Doctors said it was too dangerous to treat him with "rescue meds" at home and he can now be treated only with hospital-administered medicine.

Ms Caldwell had a batch of medicinal cannabis oil taken from her at Heathrow Airport on Monday after a flight from Canada.

Former drugs minister Norman Baker described the confiscation and "inhumane".

He said: "It is cruel and inhumane to have seized cannabis oil from the mother of Billy Caldwell as the two arrived back at Heathrow.

"The seizures the boy is now suffering are ones directly caused by the Government.

"It became very clear to me in my time as drugs minister that cannabis has useful medical properties, and indeed, that it is the only substance that works for some people, a situation widely recognised in other countries."

He added: "Billy should be allowed to be treated with cannabis oil without further delay and the Government should commit to changing the official categorisation of cannabis to recognise its medicinal value."

Ms Caldwell credits the oil with keeping her sick son's seizures at bay, saying he was seizure-free for more than 300 days while on the medication.

She added doctors in Canada and Northern Ireland familiar with Billy's case said the situation was life-threatening.

The child, from Castlederg in Co Tyrone, started the treatment in 2016 in the US, where medical marijuana is legal.

He became the first person in the UK to receive a prescription after his local GP in Northern Ireland, Brendan O'Hare, began writing scripts.

However, there is no record of a health service prescription being dispensed.

Dr O'Hare was summoned to a meeting with Home Office officials recently and told to stop.

Ms Caldwell made the trip to Toronto and back with her sick son to get a six-month supply to treat up to 100 seizures a day, but said border officials seized the oil.

She said her son was too ill to travel to Canada to get his medication.