A test in which a Weekend Herald staff member knocked back nine beers before hitting the legal limit has brought accusations from health groups that the Government is condoning drink-driving.

"It doesn't surprise me, because we have legal drunk driving in New Zealand," said Professor Doug Sellman of the Otago University-based National Addiction Centre yesterday, after being told of the supervised drinking session, held to measure what the existing limit allows.

The two staff members who took part in the session, a female reporter and a male photographer, were shocked at how drunk they became before being over the limit. Both said they would not consider driving in that state.

Photographer Richie Robinson, weighing 85kg, drank nine bottles of lager amounting to 11.7 standard drinks in just under four hours before reaching the limit of 400 micrograms of alcohol per litre of breath.

Had the limit been 250 micrograms - as recommended by the Ministry of Transport on the basis of hundreds of overseas studies but resisted by the Government pending a two-year research project on New Zealand roads - he would still have been able to drink almost six bottles.

Reporter Beck Vass, at 59kg, remained slightly within the existing limit after drinking five glasses of wine in just under two hours. She would have passed 250mcg on her third glass.

Professor Sellman said the experiment, using a commercially available breath-analyser, gave graphic evidence that "you've got to really get quite intoxicated before going over the limit".

He accused the Government of bowing to the liquor industry by resisting what the Law Commission identified as the three most important tools for combating alcohol abuse - increasing prices through taxation, reducing advertising and lowering the adult drink-drive limit.

That was rejected last night by Transport Minister Steven Joyce, who said he recalled receiving only one letter on the subject from the Hospitality Association, but hearing "much more aggressively from Doug Sellman and his supporters".

Mr Joyce said the Weekend Herald experiment showed people processed alcohol differently, and the fact that Vass was close to 250mcg after two glasses of wine reflected public concern that reducing the legal limit could prevent low-level social drinking.

A clear understanding was needed of the harm caused by drivers with alcohol levels between the existing and proposed limits, and "we don't have it in this country, nor from the Australian data".

Wide public support was also needed for any change, Mr Joyce said. "I think we need three-quarters support or more."

But Alcohol Healthwatch director Rebecca Williams said the Government was out of step with public opinion, as a survey mentioned in Ministry of Transport papers found 85 per cent of participants believed people should not be allowed to drive after having more than one or two drinks.

"Obviously the risk is relatively low with one or two drinks, but we want to keep people down in law so they are sober enough to make sensible decisions," she said.

"It isn't about wowsering - eight or nine drinks is not social drinking, it's binge drinking."

Ms Williams said the Government was sending a "seriously complicated message" by imposing a nil alcohol limit for drivers aged under 20 and but allowing adults to drive after excessive drinking.

Mr Joyce defended the Government's initial focus of introducing zero limits for young drivers and repeat drink-driving offenders, saying they were the two groups for whom fatality levels were considerably higher than in Australia, which has an adult limit of 250mcg.

But Gavin Foster of alcohol and drug-testing equipment supplier Sober Check, who helped to conduct the experiment, said the 400mcg limit was ridiculously high.

"Would a politician put their wife, partner, loved one, children in a car and let them drive off with someone who is 380mcg?"