A mother has vowed to return to Canada to get more cannabis oil used to treat her son's severe epilepsy after having a supply confiscated at Heathrow Airport.
Charlotte Caldwell made the trip to Toronto and back with 12-year-old Billy to get a six-month supply to treat up to 100 seizures a day, but said border officials seized the oil on Monday.
Ms Caldwell, from Castlederg in Co Tyrone, accused Home Office Minister Nick Hurd of having "likely signed my son's death warrant" before heading to a London meeting with him.
"It's Billy's anti-epileptic medication that Nick Hurd has taken away, it's not some sort of joint full of recreational cannabis," she told a press conference.
"I will just go back to Canada and get more and I will bring it back again because my son has a right to have his anti-epileptic medication in his country, in his own home.
"Let me tell you something now: we will not stop, we are not going to stop, we are not going to give up, we have love, hope, faith for our kids and we are going to continue."
She said Billy was due his next dose at 3.30pm, and warned of the dangers of missing his first treatment in 19 months.
"The reason they don't do it is that it can cause really bad side-effects - they wean them down slowly. So what Nick Hurd has just done is most likely signed my son's death warrant."
She said she would be meeting Mr Hurd at the Home Office on Monday afternoon to plead to him "parent to parent" to get the oil back.
Ms Caldwell, 50, said she was "absolutely devastated" to have the supply taken away after declaring it to border officials, and claimed one welled up with tears while doing it.
"They are parents themselves and they were very conflicted about removing the medication from me; in fact. one of them had tears in their eyes when he was doing it. They did not want to do it," she said.
The Home Office said it is "sympathetic to the difficult and rare" situation faced by the Caldwells, but defended the seizure.
"Whilst we recognise that people with debilitating illnesses are looking to alleviate their symptoms, Border Force has a duty to stop banned substances from entering the UK," a spokesman said.
"Ms Caldwell has therefore had cannabis oil seized this morning at Heathrow Airport upon landing from Canada."
Billy 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, Brendan O'Hare, began writing scripts.
The doctor was summoned to a meeting with Home Office officials recently and told to desist.