Bars could be able to open for 68 hours straight under a Rugby World Cup booze bill, a Ministry of Health-funded group says.
Act leader David Seymour, who has introduced the legislation, says that is possible but unlikely - and he has revealed venues will likely be allowed to choose only 16 of 48 matches to screen.
The National Public Health Alcohol Working Group is highly critical of the law change to allow all bars to stay open between 4am and 8am for World Cup matches.
The group, which is independent but funded by the Ministry of Health, submitted that the bill could see bars open for extremely long stretches.
"On the final weekend of the pool matches there is the potential for premises to open from 8am Saturday through to 4am on the following Monday, without a break, due to the scheduling of the matches - 68 hours of continuous opening," the group's submission to the select committee considering the bill stated.
"On quarter-final weekend there is again the potential for 48-hour continuous opening."
Mr Seymour said such claims were theoretically correct, but unlikely to occur.
The select committee was leaning towards allowing bars to show a limited number of games - probably 16 - with bars free to choose which matches, he said.
"It will effectively mean that you can watch all of the All Blacks games, all of the eight play-off games, and four other pool games from some other team.
"Are you going to start giving up games that very few people have any interest in watching in order to bring out this herculean all-weekend marathon session? I doubt it.
"And any bars that might do that are probably the ones that already open right up until the 4am anyway. Those are the kind of places that can already open for 40 out of 48 hours in a weekend."
National had previously stated it wanted the bill changed so that it applies only to All Blacks games and knockout matches - a total of 12 matches.
Mr Seymour's view was that only broadcasting All Blacks matches was "deeply unfair" to New Zealand's many ethnicities.
A submission from New Zealand rugby league great Kevin Tamati, now involved in the Hawkes Bay Community Action Youth and Drugs team, with Denis O'Reilly and Tipene Harmer, said the legislation was unnecessary.
"The fuss and sense of triumph around the introduction of the bill and the bill itself normalises an unhealthy connection between sport and the consumption of alcohol ... we want our young people to see sobriety as the norm rather than implicitly suggest that you need booze to have fun or to enjoy sport."
Dr Ang Jury, chief executive of Women's Refuge, said alcohol was an aggravating factor in situations of domestic violence.
The New Zealand Medical Association said it was concerned allowing pubs to stay open for the rugby would "exacerbate alcohol-related harms".