Billy Caldwell was hospitalised after his seizures grew more severe

A Tyrone boy with a life-threatening medical condition is to be allowed Cannabis treatment after the British Home Office backed down on blocking his access to it.

Sinn Féin MP Órfhlaith Begley tweeted that she had “received official confirmation that Billy is going to receive his medication and it is on its way.”

On Monday, Charlotte Caldwell attempted to bring medicinal cannabis oil into Heathrow Airport for her 12-year-old son Billy but it was confiscated after in on a flight from Canada on Monday.

Billy was taken to Chelsea and Westminster Hospital in London yesterday after the frequency of his seizures increased.

Charlotte Caldwell (left) and her son Billy at Heathrow Airport after having a supply of cannabis oil used to treat his severe epilepsy confiscated on their return from Canada, 11-06-2018. Image: Stefan Rousseau/PA Wire/PA Images

Ms Caldwell said on Saturday that he had suffered two seizures overnight but he was now stable and asleep.

She said: "Billy had two more seizures overnight which is putting him further into a crisis situation," she said.

The British Home Office said it is in contact with doctors treating Billy and is carefully considering treatment options.

Charlotte and Billy Caldwell, who was taken by ambulance to a London hospital after his cannabis oil treatment was confiscated, 15-Jun-2018. Image: Yui Mok/PA Wire/PA Images

"This medicine was anti-epilepsy medicine,” Ms Caldwell said from outside the hospital.

“He has to have it every day. He needs it as soon as possible. We are hoping for a resolution today."

"I am confident we are going to get this done. The medical teams are working closely with the Home Office. We are praying for a miracle."

Sinn Féin MP Órfhlaith Begley welcomed "confirmation" that Billy would now get his treatment.

"Billy should never have been put in that position.

“The treatment was clearly working for him and he deteriorated badly once it ended, yet it still took intense lobbying to get the Home Office to reverse this cruel decision."

Ms Caldwell praised medical teams at the Chelsea and Westminster Hospital.

"The staff here have been amazing,” she said.

“He is getting the best medical care in the world. I cannot thank the staff at the hospital enough."

Billy, who is also autistic, with pronounced communication difficulties, suffered back-to-back seizures on Friday after being seizure-free for more than 300 days when he was previously given the cannabis oil, according to his family.

He was given a prescription for medicinal cannabis oil last year to help treat his epilepsy - the first time the drug had been prescribed by the NHS.

But the boy's doctor was told by Home Office drug enforcement teams to stop prescribing the medication, which Ms Caldwell credits with keeping her son's seizures at bay.

The family had planned to return to Canada if they could not get the medicine in the UK but say Billy is now too ill to travel.