A six-year-old boy with epilepsy is to present a petition to No 10 on Tuesday calling for him to be granted a special licence to use medical cannabis.
Alfie Dingley has a very rare form of the illness that causes up to 150 seizures per month.
His parents want the government to let him use cannabis oil – which is banned in the UK – to help with his symptoms.
Earlier this month, ministers said they were “exploring every option” after meeting with the family.
Alfie and his mother, from Kenilworth in Warwickshire, will present the petition, which has more than 370,000 signatures, to the government.
His family, who have booked a room in Parliament for the day, said thousands of Alfie’s supporters have written to their local MPs urging them to meet the family.
‘Time for compassion’
Cannabis oil is available for medical purposes in the Netherlands.
Alfie’s family have previously travelled there to get him cannabis-based treatment and said the results were “dramatic” – reducing his seizures in a month to only one that was less severe.
Alfie’s mother, Hannah Deacon, said: “This isn’t a time for bureaucracy – this is a time for compassion.
“I don’t want to break the law by going to Holland and bringing his medical cannabis into the UK illegally. And why should I have to do that?”
The petition comes after former justice minister Mike Penning urged the Home Office to grant the licence “immediately”.
He said although there was substantial evidence that cannabis was a harmful drug, “surely in the 21st Century we can find an acceptable way to separate the two, so that patients who gain relief from the use of the drug are legally and safely able to do so”.
Earlier this month, the Home Office said it was considering allowing a medical cannabis trial to treat Alfie. However, it has stressed that “no decisions have been made”.
It has previously turned down requests by the family to legally take the drug, saying that cannabis cannot be practically prescribed, administered or supplied to the public and can only be used for research under a licence.
At the time a spokesman said it was important that medicines are “thoroughly tested to ensure they meet rigorous standards before being placed on the market, so that doctors and patients are assured of their efficacy, quality and safety”.