MPs and lobby groups say once-in-a-generation alcohol reforms must be salvaged after one of the core measures was defeated in Parliament.
Justice Minister Judith Collins said yesterday that Parliament's decision not to raise the alcohol purchase age in a conscience vote had denied the Government an effective way of curbing alcohol-related harm.
But she felt there were many more effective tools in the bill.
National MP Tim Macindoe, who tabled the amendment to raise the purchase age to 20, said it was now crucial "to get the rest of the bill right".
Asked whether the legislation needed stronger amendments to make up for the drinking age being kept at 18, he said he had confidence in the Justice Minister's proposals.
The minister has proposed banning alcohol advertising that targets young people and requiring parents to give express consent - verbal, written, or by text message - for the private supply of alcohol to people under 18.
Health experts, including the Prime Minister's science adviser, Sir Peter Gluckman, had strongly supported a purchase age of 20.
University of Otago head of preventive and social medicine Jennie Connor said the bill had already needed more robust measures to curb alcoholism - with the age option defeated, it was absolutely essential.
She did not believe the bill in its present form would limit alcohol-related damage.
MPs will now consider the remainder of the bill, which includes banning late-night alcohol sales and limiting where alcohol can be displayed in stores.
They will also consider 18 amendments put up by MPs who have proposed a minimum price for alcohol, warning labels for liquor bottles and stricter rules on alcohol sponsorship and advertising.
The purchase age was the only amendment on which all parties had a conscience vote.
The National Party plans to vote as a party for the remaining proposals, while Labour will allow a personal vote for all amendments.
Mrs Collins has confirmed that National would vote against all 18 amendments proposed by other parties.
This meant National needed two more votes to defeat the other parties' amendments, and the key votes would fall to coalition partners Act and United Future.
Both Act leader John Banks and United Future leader Peter Dunne said they would not support any of the amendments.
Labour spokeswoman Lianne Dalziel said the fact that National was "whipping" its vote meant the bill was no longer in the hands of politicians.
She urged constituents to lobby their MPs for stronger measures.
Ms Dalziel felt the bill was out of tune with what the public wanted and was "disrespectful" to submitters who called for changes to alcohol pricing, sponsorship and availability.
A Herald-DigiPoll survey showed 80 per cent of New Zealanders supported a higher purchase age. But the DigiPoll also showed just 40.6 per cent of the public supported a minimum price on alcohol.
Hospitality Association chief Bruce Robertson welcomed the vote on the purchase age but said the industry was awaiting the rest of the reforms with some trepidation.
He was most concerned about a law change giving communities the power to set their own local alcohol policies, which he felt would create new, complex systems which would inevitably increase licensing fees.
MPs want 18 amendments to the Alcohol Reform Bill. Here are some, and what the Ministry of Justice thinks.
Set a minimum price for alcohol
MoJ: Too early for a minimum price as officials are investigating whether it works.
Ban alcohol advertising and sponsorship
MoJ: Strong public support but would penalise many clubs and organisations.
Ban alcohol advertising on radio and TV
MoJ: Strong public support but little evidence it works.
Remove industry exemption from providing nutritional and warning labels
MoJ: Needs approval from Australia, which shares food safety standards. Should not be part of this bill.