Wellington, June 15 NZPA - The orange man who reminded everyone to vote in the general election is back -- this time he wants to make sure you are enrolled to vote in the referendum on smacking.

The citizen initiated non-binding referendum is the result of a petition. It will ask: "Should a smack as part of good parental correction be a criminal offence in New Zealand?"

The referendum will be held by postal ballot from July 31 to August 21.

The last day to enrol is July 30 and an advertising campaign has begun today in print media, on television, radio and the internet to remind people to enrol and update their details.

Almost 36,000 people have become eligible to vote since the general election.

Chief Electoral Officer Robert Peden said the campaign and voting process would cost $8.9 million.

The aim was to make it "as easy as possible" for people to enrol and vote, he said.

A preliminary result is expected on August 21 and a final count on August 25, after papers are received from overseas.

The referendum would be the first citizens initiated referendum to be held via post, Mr Peden said.

However, there was no reason to doubt the security of the process, he said.

The last postal referendum, initiated by the Government, was held in September 1997 on whether to have a compulsory retirement savings scheme. More than 80 percent of enrolled voters had their say and the majority (91.8 percent) said they did not want one.

Child advocates have already begun the call for a "yes vote" on the new referendum.

Barnardos chief executive Murray Edridge said voting yes in the referendum was the "best way to ensure the legal protection of children".

"The referendum question is designed to confuse people.

"It suggests that hitting children is part of good parenting when there are clearly better alternative practices."

It also suggested good parents would be criminalised by the law but police statistics showed that was not happening, Mr Edridge said.

Plunket chief executive Jenny Price agreed and said there were safe and effective measures for disciplining children that did not involve physical violence.

Parents Centres, a provider of childbirth education, said the referendum was a "tedious process".

Chief executive Viv Gurrey said it was "nonsense to re-litigate and at great expense, a law that is working as it should".

New Children's Commissioner John Angus said he supported the law as it stands.

"It's up to the Government to determine how they respond to the outcome of the referendum, but it won't change my advice to the Government and my statements that I think the law as it currently stands is satisfactory and is a good piece of law for the children of New Zealand."

He said children deserved the same legal protection against assault as adults did, and suggested smacking wasn't especially effective.

Family First national director Bob McCoskrie said the law was "confusing" and the confusion was "causing huge harm".

"Appropriate smacking for the purpose of correcting, training and teaching should never be a crime, exposing parents to possible police investigation and CYF intervention," he said.

"The law is fundamentally flawed because it fails to deal with the problem it was supposed to -- child abuse -- and implicates law-abiding parents in the process."

Family First supported the petition that led to the referendum.

Green Party MP Sue Bradford, who introduced the changes to the law, said the amendment "simply removed a defence of `reasonable force' for the purpose of correction which allowed some parents to get away with assaulting their children".

"This then meant that police often didn't take prosecutions when they perceived the reasonable force defence could be used."

The law was supported by 113 MPs across Parliament.