Launching advocacy group The Med Shed at the Hellenic Club in Woden on Sunday afternoon, group co-ordinator Matthew Holmes said a large number of pain, nausea and seizure sufferers were forced to break the law to seek relief. Despite overseas evidence of the drug's effectiveness, the medical community in Australia remained slow to accept it as a viable treatment option.

By establishing the group they wanted to take advantage of the October ACT election to pressure candidates and parties to change the law and make cannabis use legal for medical purposes in the ACT.

In February the Senate passed changes to the Narcotic Drugs Act that will allow cannabis to be grown legally for the first time in decades. A national body will be established that can issue licences to growers and regulate local crops of medicinal marijuana, however possession and use remain illegal. Federal Health Minister Sussan Ley said in February that the Department of Health and the Therapeutic Goods Administration were well advanced with plans to help lower barriers that prevented cannabis access for those with a genuine medical need.

But Mr Holmes said the changes were not happening fast enough, and called on ACT Justice Minister Shane Rattenbury, a supporter of medicinal cannabis use, to provide an amnesty from prosecution for those currently using the drug.

"We do think Canada has the best arrangement (for providing cannabis to patients) and we'd like the Assembly to take us to a similar model," Mr Holmes said.

"However, if that doesn't come about in the one-to-two-year timeframe we will take matters into our own hands and we do have the support to open a dispensary."

Twenty-one-year-old chronic pain sufferer and cannabis oil user Laura Bryant told the group that she wanted to see the dispensary opened by 2017. Ms Bryant said since deciding to go public with her own story through The Canberra Times last year she had been overwhelmed with people wanting more information and to get help.

"Eighteen months ago I would have to crawl the 12 steps from my bedroom to the toilet some days. I'm now studying nursing and paramedicine, I've moved out of home, things that no one thought I would ever be able to do. But I live in constant fear of being arrested," she said.

Laura's mother Bernadette Bryant, who had spent years acting as her daughter's primary carer, said the group wanted to offer legal, medical and moral support to those with a need for access to cannabis.

"My life's plans never included watching my husband roll a joint for my daughter ... but this drug was life-saving and has given our family our lives back," she said.

Mrs Bryant said the group was organising a petition to be presented to the Legislative Assembly, seeking advocates and support from across the community to attend public events.

Mr Holmes said the group was also planning to establish a centre where those in need could visit once a week to meet qualified doctors and seek advice on whether cannabis might be a suitable treatment for their condition.

ACT Justice Minister Shane Rattenbury could not be reached for comment.