Some of Australia's most high-profile medicinal cannabis advocates have banded together to launch a new campaign for better access to the drug.

Key points: Federal legislation was to give patients, doctors access to a safe, reliable, legal cannabis source

Federal legislation was to give patients, doctors access to a safe, reliable, legal cannabis source Patient advocates say there are too many obstacles in obtaining the drug legally

Patient advocates say there are too many obstacles in obtaining the drug legally Advocates want an amnesty on black market supply while a legal supply chain is established

Federal legislation passed last year was supposed to give patients access to cannabis for medicinal use but Lucy Haslam and Barry Lambert said it was harder to get than ever before.

They are asking Prime Minister Malcolm Turnbull for an amnesty on compassionate suppliers and for new Federal Health Minister Greg Hunt to take this opportunity to fix the regulations.

The Greenlight campaign kicked off last month with a full page ad in a major metropolitan newspaper featuring Mr Lambert's five-year-old grand-daughter, Katelyn, who has a severe form of epilepsy known as Dravet Syndrome which causes developmental problems.

The ad asks the Prime Minister and state Premiers to make it legal for Katelyn to eat cannabis extract which her family said greatly reduced the number of seizures she experienced.

"Her improvement has been dramatic since she's been on medical cannabis," Mr Lambert said.

He had previously donated $33 million to the University of Sydney to fund research into medicinal cannabis but said the Federal and State Governments needed to change the way they scheduled medicinal cannabis.

"The laws in this country for medicinal cannabis don't work for the benefit of the consumer and they don't even work if someone wants to grow it either, so it's a complete joke both at the federal and state levels and that needs to change," he said.

Lucy Haslam (R) hugs Katelyn Lambert. ( ABC News: Meredith Griffiths )

The Greenlight campaign has been devised in conjunction with Epilepsy Action Australia.

The campaign is inviting people from all over Australia who already use medicinal cannabis to share their stories on a website and then come together for a public event in two weeks' time.

Ms Haslam has been campaigning for medicinal cannabis since her son, Dan, found it eased his suffering when he was dying from cancer.

She told the ABC she was concerned that obstacles preventing patients having access to the drug were increasing despite Federal Parliament legalising medicinal cannabis last year.

"I just can't sit quietly and be happy and congratulate the Government on what they've done because you know, for people like Katelyn, there is no access," she said.

"For every other Australian patient at the moment access is very poor and that's something that really I think is untenable and have to do something about."

'Stop the raids on compassionate suppliers'

The campaign launch had been brought forward after recent raids on organisations in Newcastle, Adelaide and the Sunshine Coast that had been supplying medicinal cannabis to patients.

"We need to stop the raids on compassionate suppliers — I mean there's a very big difference between people that are supplying a criminal recreational market and people that are supplying for compassionate access, so we need to take that criminality away out of what's happening at the moment because at the moment it is meeting a medical necessity," Ms Haslam said.

Mr Turnbull recently rejected calls from One Nation for an amnesty on medicinal cannabis, saying it would be irresponsible.

Ms Haslam said he needed to rethink his stance.

"For any young child who has had their black market supply of cannabis interrupted, there is the potential for a catastrophic event for one of these young children and who is going to be responsible for that? That would be my question to the Prime Minister," she said.

'Current laws not working'

Federal legislation came into effect in October which the Government said would "give patients and doctors access to a safe, reliable and legal source of cannabis for medicinal use".

But Ms Haslam said the Government had failed to consult broadly and it drew up the regulations before establishing the expert advisory council it had promised.

(L to R) Joy Lambert, Michael Lambert, Lucy Haslam, Katelyn Lambert and Barry Lambert. ( ABC News: Meredith Griffiths )

She advised Mr Hunt to seek advice from all sides of the debate, including experts from Israel, the United States or Canada, where medicinal cannabis is an accepted therapeutic practice.

"I think very much it's clear the Government is being influenced by, I would say, by a conservative medical profession who don't know anything about it," she said.

"They mistake their authority for expertise. There is no, or very few, Australian medicos who have any expertise in medical cannabis."

Mr Lambert said last year's legislation had actually made it uneconomical to grow cannabis.

He has invested in a company, Ecofibre, which has been growing hemp in Australia for years but which has now moved its operations to the United States.

Mr Lambert said his financial interest in Ecofibre had not influenced his involvement in the Greenlight campaign.

"Obviously no, this is all about Katelyn and compassion. I don't need to have vested interests in this, it just so happens that I helped out another business, and that business by the way is unprofitable so we're still helping them out," he said.