Helen Kelly says she is "more determined than ever" to campaign for access to cannabis after a difficult few weeks without it overseas.

The terminally ill former Council of Trade Unions president has been in Cuba receiving "last ditch" treatment for lung cancer.

She has been unable to access cannabis since she left New Zealand around August 23, and in a Facebook post said she has had a "very tough time with pain" while overseas.

Kelly said she has been taking morphine every four hours instead of once or twice a day when she has access to cannabis.


"I need my cannabis and am more determined than ever to campaign for it. It is obvious to all who spend time with me how well I was doing on it," she said.

"We need a legal supply. There are so many people telling their stories they need a regular, reliable, affordable supply."

She said attempts to legally bring cannabis back into New Zealand through a loophole was proving too difficult

Kelly said the treatment in Cuba for her terminal lung cancer was still in trial, and while not being sold as a cure has had positive trial results.

"For me it was after running out of options. But the results from the trials has made it something I want to give a go ... The results to date are promising and give some advantage to most [people]."

However, in yesterday's Facebook post she said the results so far weren't looking successful. She returns to New Zealand on the 19th.

Kelly has vowed to run a referendum in the 2017 general election on the legal status of cannabis.