Former Prime Minister Helen Clark says if the country wants to keep its "clean, green reputation" it had better move forward with a plastic bag ban.
"If we're going to deal with this plastic bag menace then it's going to need the Government to act in some way," Ms Clark told The AM Show on Tuesday.
"For our country's reputation of being clean and green we better put some substance around it."
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A Greenpeace-driven petition, 'Ban The Bag', now has more than 65,000 signatures and will be presented to Conservation Minister Eugenie Sage on Tuesday.
Prime Minister Jacinda Ardern told The AM Show the Government is finalising a strategy to manage the issue.
"It's one of the things I would say I probably get the most correspondence from, the most letters from children. They write to me about straws that affect turtles and bags affecting sealife.
"What we have at the moment is inconsistency, so that's one of the things that we need to work on.
"For instance, individual supermarket chains who are doing a fantastic job in deciding they're not going to use them or that they'll charge for them.
"But we don't have a uniform approach.
Ms Clark says other countries are miles ahead of us on the issue.
"We need to look at the many other countries around the world that are taking action.
"We know that these bags can apparently take up to 1000 years to degrade... which is horrific."
Greenpeace spokesman Phil Vine told the show even unassuming countries like Rwanda and China have imposed a ban.
"We are behind the rest of the world.
"[Jacinda Ardern] just needs to move on this because the weight of public opinion... believes we have too much plastic in their lives."
Mr Vine says we only use so much plastic out of "habit" and we need to "realise the cost every time we get one".