The youth wings of four political parties, including National and Labour, have joined forces to urge MPs not to change the legal drinking age.
MPs are considering legislation that would allow 18-year-olds to continue to buy alcohol at pubs and restaurants but would make them wait until they are 20 to do so at a supermarket.
In a joint submission on the Alcohol Reform Bill, representatives of the youth wings of National, Labour, the Greens and ACT argued there's no evidence that changing the drinking age will reduce alcohol-related harm.
They also say it would punish responsible drinkers for the behaviour of a few.
Binge drinking is a society-wide problem, the submitters said, and young drinkers are being made into a scapegoat.
The president of ACT on Campus, Peter McCaffery, told MPs that there are people harmfully drinking in all age groups, and objected to "banning an entire group of people, most of whom are drinking responsibly".
But in his submission, one of Parliament's most senior members, Jim Anderton, urged MPs not only to raise the age to 20 across the board but to ban alcohol advertising and lower the blood-alcohol limit for driving.