The Government's decision to shelve plans to lower the drink-driving limit for adults and instead do more research has been attacked as a gutless act that will leave it with "blood on its hands".

Alcohol health groups yesterday reacted with anger at the Government's plans to leave the limit at 0.08g of alcohol per 100ml of blood.

But it is imposing a zero-tolerance policy for motorists under 20 and repeat drink-drivers.

The Government was considering lowering the adult limit to 0.05g, but Transport Minister Steven Joyce said he needed more public support and research into whether drivers with a level between 0.05g and 0.08g were involved in many crashes.

Alcohol Healthwatch director Rebecca Williams called the Government "gutless" as there was already ample evidence and public support for lowering the limit.

"This is a regrettable failure that leaves our Government with blood on its hands."

Professor Doug Sellman, from the National Addiction Centre, said the Government lacked leadership, and the Alcohol Advisory Council said the decision was disappointing.

The Ministry of Transport has calculated that lowering the limit to 0.05g and increasing enforcement and public awareness would save 15 to 30 lives a year and prevent 320 to 686 injuries.

The Drug Foundation says there have already been 300 studies in the past 50 years into lowering the limit, and six of eight overseas jurisdictions showed positive results after reducing the limit to 0.05g.

Mr Joyce acknowledged advice that lowering the limit would save lives.

"They also tell you that if you didn't allow anyone to have any alcohol, you would save more lives, and if you actually didn't let anybody drive, it would save the lot."

From next year, drivers in accidents will be subjected to two compulsory breath tests. If they pass the first, they will have to do a second to see if their blood-alcohol level is between 0.05g and 0.08g.

This information, which will be publicly available, will be recorded for two years.

Mr Joyce said he suspected the threshold would be lowered to 0.05g over time, but before then the Government needed "more information and more public acceptance than we currently have".

He said there was public concern about drinking two drinks in an hour and being over the limit.

Other changes will mean drivers under 20 will not be able to have a drop of alcohol before driving.

People on a second drink-driving conviction will also face a zero limit for three years, following a period - set by the courts - of no driving for at least a year.

Judges will decide whether to impose interlocks on drink-drivers, normally after a second conviction.

Interlocks are devices that allow a car to be started only if the driver passes a breath test.

Drivers will have to pay the $150-a-month bill for the interlock, which they will have for at least a year following a three-month disqualification period.

They will have to earn their way off the interlock programme by going six months without an interlock violation, or three months if they have done an alcohol assessment.

Mr Joyce said there were checks - including taking photos - to ensure that drivers could not bypass the interlock breath-test by getting a non-drinking friend to breathe into it.

The maximum penalties for dangerous and/or drink driving causing death will be doubled to 10 years in prison.

Mr Joyce has previously called the current limit ridiculous, but said yesterday that he was only referring to himself.

"It's ridiculous for me to drink three-quarters of a bottle of wine and then drive after an hour and a half. That is my personal view and I won't be doing that, and I don't do that."

The Labour Party wants the legal blood-alcohol limit lowered, but the Automobile Association supports more research.

Prime Minister John Key said he hoped the changes would make a dent in New Zealand's drink-driving record.

"It is worrying to me that last year, 36,000 New Zealanders were convicted of driving with an excess alcohol level. On any given day, 100 drivers are being caught over the legal limit."