Outspoken left-wing feminist parliamentarians and the conservative right have joined forces to call for an inquiry into porn.

Family First spokesman Bob McCroskie has presented a petition to Parliament on the issue supported by an unlikely coalition of Labour MPs Louisa Wall and Aupito William Sio, Green MP Jan Logie, National MP Chester Borrows, NZ First's Ria Bond and Maori Party co-leader Marama Fox.

McCroskie said he believes porn should be treated as a public health issue similar to obesity and smoking, saying it was creating ''hyper-sexualisation'' of teenage boys and more research was needed into its effect.

He said an expert panel of health, science and psychology experts and counsellors should undertake an inquiry into the societal harm of porn and propose solutions.


He said he was not trying to censor all porn and he had viewed some himself.

"I've probably watched more porn because it has been targeted at me or I've stumbled across it, so porn has come looking for me ... but blood wouldn't be flowing through my veins if porn wasn't attractive."

He said the question was what harm it did.

"We've acknowledged the obesity epidemic, and we're not against food. But we do need to acknowledge when something gets harmful.

"Today's pornography is far more explicit and its also aggressive. That's what people are concerned about and the effect it is having on attitudes."

McCroskie said porn was also easily obtainable online for free.

"A lot of parents are concerned about what their children are able to access. And often they don't go looking for porn, the porn comes looking for them.

"Many families don't want the porn industry determining the values of their kids."


Logie said she suspected there might be a different understandings of what was pornography.

"We wouldn't necessarily in the Greens be having a starting point of assuming all erotic representations of sex are bad."

However, she said there was concern about sexual violence and addressing the harm where it existed.

Borrows said he was not speaking on behalf of the Government and did not know what its stance on the inquiry was, but MPs across Parliament were concerned.

"The point is we are not talking about a couple of well-read Playboys tucked under a kid's bed now. We are talking about people able to look at pornography on their telephones and computers which can't be monitored by those in charge of them."

"Parents are frequently negligent in passing on to their children the ramifications of pornography and we have to recognise the law hasn't kept up with technology has taken us."


Sio said the petition and wide range of MPs supporting it reflected concerns in the community about the link between porn and sexual violence.

"If we are going to tackle sexual violence meaningfully we do need to have the evidence before us."

Last year Auckland Grammar principal Tim O'Connor started a ''healthy relationships'' programme for students, teachers and parents which included education about porn addiction.

McCroskie said he believed it was an important step to take.

He said a societal response was needed, including education and parental responsibility, but the government had a role as well, such as regulating the responsibilities of internet providers.

He suggested an ''opt out, opt in'' choice for internet providers in which porn was blocked unless someone proactively opted in, something being trialled in the UK.


Prime Minister Bill English has said he does not see the need to boost the requirements for what schools offer by way of sex education, saying he does not think it is a fast-growing problem.

The petition was signed by 22,334 people and will go to a select committee to consider.