Key Points:

New Zealand voters may get the final say on Green MP Sue Bradford's controversial "anti-smacking" bill if an estimated 303,000 of them sign petitions launched yesterday to force two referendums on the issue.

Howick mother-of-two Sheryl Savill and former United Future MP Larry Baldock seek signatures to hold the two citizen-initiated referendums asking:

* Should a smack as part of good parental correction be a criminal offence in New Zealand?

* Should the Government give urgent priority to understanding and addressing the wider causes of family breakdown, family violence and child abuse in New Zealand?

The Government will have to hold the referendums if the petitions are signed by at least 10 per cent of those on the electoral rolls within a year of the proposals being gazetted.

Clerk of the House David McGee approved the proposals' wording on Wednesday and expects to advertise them in the Gazette next Wednesday, giving the proponents until February 28 next year to get their signatures.

There were 2,893,017 people on the electoral rolls on January 31 and a further 137,180 people who were believed to be eligible but not enrolled. This means the organisers need the signatures of about 303,000 enrolled electors.

Mr Baldock said he hoped to get as many signatures as possible before the final vote in Parliament on Ms Bradford's bill, which would remove a defence against assault charges where parents used reasonable force to "correct" their children. The bill passed its second reading in Parliament by 70 votes to 51 on Wednesday.

"We expect the bill is going to carry on until at least May, so we have 2 months to collect the 300,000 signatures," he said.

He said the first referendum in Mrs Savill's name, restoring a right to smack as a "correction", would be dropped if Ms Bradford's bill was defeated. But the indications yesterday were that the bill would pass narrowly.

Mrs Savill, 37, whose children are 8 and 10, administers a parent education programme called "How to drug-proof your kids" for Focus on the Family, the local branch of a United States-based Christian organisation. Her husband, Philip Savill, is a community constable in Howick.

"I'm a concerned mum. This is defending the way that I'll be raising my children," she said.

"I have on occasion used smacking. It's not the only thing we do, we use a whole variety of things from time-out to withdrawal of privileges. I think it's something parents should have the choice about."

She said child abuse was caused by drugs and alcohol, family break-up, poverty and stress - not smacking.

That was why she worked on helping parents keep their children off alcohol and drugs.

"I want to be able to help parents to stop their children going down that track," she said.

Mr Baldock said the second petition, in his name, showed that the initiative supported constructive alternatives to deal with child abuse, such as television advertising, pre-marriage education on resolving conflict without violence, and more funding for church and community agencies to provide "super-nanny-style" support to parents.

He and fellow MP Gordon Copeland failed in their last attempt to get a citizen-initiated referendum, to repeal the Prostitution Reform Act, in 2004. They gathered more than 200,000 signatures but it was not enough.

This time they are backed by Focus on the Family, Family First, For the Sake of our Children Trust, the Sensible Sentencing Trust and the Vision Network of evangelical churches.