Labour has no intention of backing potential coalition partner the Greens' policy of decriminalising cannabis Leader David Cunliffe says.

Decriminalisation of the drug has been a Greens policy for years but the party has avoided making it a high profile issue for some time.

With Labour's recent clarification of its cautious support for deep sea oil drilling emerging as a potential stumbling block for any post-election talks with the Greens, Mr Cunliffe has been asked about his party's stance on cannabis law reform as another potential difficult topic for the two parties.

"People can put on the table what they want to put on the table", he said yesterday.


"Labour's policy is not to decriminalise cannabis. That is not our intention."

However he confirmed that like alcohol and other "vices" any cannabis law reform legislation that made it to Parliament would be a conscience vote for his MPs.

"It's not for me to change that now."

Greens Co-leader and former Aotearoa Legalise Cannabis Party member Metiria Turei said cannabis law reform wasn't one of her party's major priorities, "but it is our policy and we're not ashamed of it".

At least some of Mr Cunlife's MPs want the issue examined.

Palmerston North MP Iain Lees-Galloway last year said cannabis would be "a good candidate" for evaluation under new legislation to regulate legal highs proposed by former associate Health Minister Peter Dunne.

"It should be science and not politics that determines the relative harms of specific drugs", Mr Lees-Galloway said at the time.