They have watched on helplessly as their 24-year-old son Dan endures a torrid battle with chemotherapy, his last-ditch hope of fighting off the bowel cancer doctors say will eventually kill him.

Despite being prescribed a barrage of legal drugs, his only relief from the crushing nausea of chemo comes in the form of marijuana, a substance the Haslams are being forced to buy on the black market.

The family has now made an impassioned plea to NSW Health Minister Jillian Skinner to decriminalise cannabis for terminally ill patients, with a petition launched this month already attracting 7500 signatures.

“We’ve been through so much watching our son suffer and we’ve finally found something that is giving us hope where doctors can’t,” Mrs Haslam said.

“We’re not saying make it legal for recreational use, but it’s ridiculous that you can get Oxycontin or methadone legally for medical reasons but not cannabis.

“I shouldn’t be made to feel like a criminal for buying it.”

A state Senate committee last year unanimously backed a move to decriminalise cannabis for terminally ill patients, but the health minister remains unmoved.

“To see people from all corners of the political spectrum support it and then one ignorant woman say no is very disheartening,” Mrs Haslam said.

“The conversation must start happening. This has to be an election issue and the public should get behind it.”

Dan had never even smoked a cigarette before medicinal marijuana was recommended to him as a nausea treatment by Dwone Jones from 360 Fitness, who had previously battled bowel cancer.

“My immediate reaction was ‘no way’; dad was the head of the Tamworth drug squad in the police force and I’d grown up in a very straight-edged family,” Dan said.

“But the chemo was just horrible. I was losing six kilograms on my chemo weeks because I couldn’t eat and I felt like I was being poisoned from within.”

The Haslams were so desperate for Dan to get relief, they relented and allowed him to try marijuana for the first time last October.

“The first time I smoked it, I managed to light my stubble,” Dan said.

“But the difference in how I felt was amazing; it can’t be understated.”

Rather than check straight into hospital after chemo to be hydrated intravenously, Dan was able to go straight home and eat.

He hasn’t vomited since using the drug.

The family is also hopeful the cannabis oil extracted from the plant could actually help reverse the cell damage in Dan’s body caused by the cancer.

Ms Skinner said it was critical “full and frank information” was available before the government rushed headlong into decriminalising cannabis.

“I have written to the federal government to request support for further clinical research to support the development of pharmaceutical-grade cannabis medicines,” Mrs Skinner said.

“With only limited scientific evidence available on the safe use of crude cannabis, the NSW government is unable to support the remaining four (Senate) committee recommendations, which seek to decriminalise the use of crude cannabis for selected patient groups based on medical approval. 

“There are safe and effective medications currently available for most of the symptoms and conditions that medicinal cannabis is purported to be effective in treating.”

To sign the petition, visit www.dansstory.com.au