The Harmful Digital Communications Bill before Parliament now may end up penalising children who do not fully understand the consequences of bullying.

A new law to tackle cyberbullying comes before Parliament this week amid concerns it is too harsh and will "criminalise children".

READ MORE: Opinion: Legislating the internet

MPs will debate the second reading of the Harmful Digital Communications Bill on Tuesday. It will create a new offence of sending messages or posting material to cause harm, punishable by up to two years in jail or a $2000 fine.

Inciting someone to commit suicide will carry a maximum three-year jail sentence.

Karla Sanders, of anti-cyberbullying project Sticks n' Stones, is worried it could see teenagers punished by the courts for online behaviour.

"What I'm against is criminalisation of people as young as 14 who may not fully understand the impact of what they have said online.

"If two girls had a set-to in the playground at high school they would not have the same kind of punishment. So what are we saying - the consequences for behaviour online is going to be greater than it is in the real world?"

The teacher and project facilitator voiced her concerns to Justice Minister Amy Adams late last year.

Sanders is worried the creation of a new offence of incitement to suicide will unfairly target youngsters.

"When we are talking about a 14-year-old who says: 'you should kill yourself, the world will be better without you' is there intent with that text message for that person to go and take their own life?" she asked.

"This is an incredibly emotive issue."

She also pointed to a lack of training for teachers: "Unless we are committing similar focus, funding and resources towards education then, essentially, what we are doing is criminalising children as young as 14 rather than enabling them to understand the impact their actions and words have in an online environment, which we can sometimes feels is removed from what we would do or say in the real world."

However, Adams says children - or those under 14 - cannot be charged with the offence.

"This scaremongering is typical of the types of misinformation the large multinational internet companies are pushing," she said.

"The decision to prosecute anyone rests with the police, who are required to ensure any prosecution is in the public interest.

"The police, for example, exercise their discretion and don't charge every 14-year-old with assault when there is an instance of physical bullying, often employing other means such as pre-charge warnings and diversion to address a child or young person's offending, and I trust them to continue to use their discretion in respect of cyberbullying."

Existing laws dealing with incitement do not require intent, she says.

"The courts in interpreting existing legislation have through case law read intent into it and it is anticipated they will do the same with this new provision."

Online tormentors can also be reported to a new agency that will mediate complaints. The role is likely to go to watchdog Netsafe.

Adams said the new "approved agency" will be required to educate the public.