Green Party MP Nandor Tanczos is pushing for instant fines for cannabis use by adults rather than a criminal conviction.
The partial decriminalisation proposal comes in a member's bill, which will form the basis of the Greens' cannabis policy.
The bill would introduce $100 instant fines for people over 18 found with up to 28 grams of cannabis, or those growing up to five small plants at home for personal use.
Anyone smoking or growing cannabis within 100 metres of a school would be fined $500, in addition to existing penalties. Selling any amount of the drug would remain illegal.
Tanczos says his proposal to partially decriminalise cannabis is moderate and a practical solution to the political impasse on the issue. He says the current law wastes huge amounts of police time and resources and he says instant fines would still send a symbolic message to discourage cannabis use.
But National says any move to decriminalise cannabis would result in more young people using the drug.
National families spokesperson Judith Collins believes such a move would be dangerous and she says if Labour forms an alliance with the Greens after the election then the cannabis laws would change.
However, Prime Minister Helen Clark is downplaying any potential problems dealing with the Green Party over cannabis, after the election.
Helen Clark says the cannabis laws are not an issue that is raised often with her by the public. She says it is unlikely cannabis would be dealt with as a government issue and is more likely to be handled through a conscience vote.
United Future says the Green Party's plan is the thin end of the wedge and retaining the current law will remain a bottom line for the party.
Under United Future's support agreement with Labour, the government is committed to retaining the current cannabis laws. Party leader Peter Dunne says his party will insist on the same deal in any post-election negotiations.
