Green MP Chlöe Swarbrick will need most of Labour's MPs to swing behind her alcohol harm reduction bill, if it is to pass its first hurdle in Parliament.
Swarbrick's member's bill would ban alcohol sponsorship in sports and give local councils the power to control alcohol sales, trading hours and locations.
Its success, when put to a conscience vote at first reading in the coming weeks, will be up to Labour's caucus, given National and ACT are block-voting against it.
Labour's Manurewa MP Arena Williams accepted a petition by Alcohol Healthwatch and Hāpai Te Hauora supporting the bill at Parliament yesterday.
Williams told RNZ her constituents had raised concerns with her about late opening hours at bottle stores and Auckland Council's inability to change them.
"When you have communities like Manurewa asking the council to do something about it and the council just can't, that to me says there's an issue with the law.
"And we as Parliamentarians need to get our heads together and figure out a solution no matter whether we're Labour, Green, National or ACT."
As well as banning alcohol advertising in broadcast sports, Swarbrick's bill would put a stop to special appeals that prevent local councils from setting up their own alcohol policies.
The legislation is strongly supported by Māori public health organisation Hāpai te Hauora chief executive Selah Hart who said she wanted to see cross-party support for the bill.
"This is the most harmful legal drug that sits within Aotearoa New Zealand. We just came off the back of two-and-a-half, three years, of putting health first in our Covid response. Why aren't we doing the same with alcohol?"
National and ACT's caucus' will be 'whipped' for the first reading with MPs voting according to their party's line, while Labour MPs will cast votes based on their individual views.
Those opposition block-votes mean the majority of Labour's caucus will have to support Swarbrick's bill if it is to reach select committee.
Many Labour MPs don't know where they sit yet; Nanaia Mahuta said she would take stock of the debate while David Clark and Michael Wood said they were undecided.
Justice Minister Kiri Allan said she would not support the bill because the government had a plan to introduce its own alcohol harm reduction legislation.
Sports Minister Grant Robertson has voted in favour of banning alcohol sponsorship in the past but does not support this bill over concerns it will impact sports funding.
"I've got some sympathy with the first part of the bill around local alcohol plans but I think around the question of sponsorship I want to work through that issue more deliberately than just passing this piece of legislation."
Robertson said the financial support sports advertising generated - estimated some years ago to be $20 million annually - was "significant", despite not having up-to-date figures.
Yesterday's petition was signed by more than 8000 people and endorsed by organisations like the Salvation Army but it is the votes inside Parliament that count.
Swarbrick said it was "incredibly clear" profit had been prioritised over communities and she was positive she could rally the votes to get her bill past its first reading.
"These are interventions that are evidence-based, that are cost-effective and have been recommended to governments of both stripes over the past two decades.
"We can get it done and I believe that if MPs reflect on their consciences and on the evidence then we will get it through first reading in the next month."