Campaigners against plea bargaining have marched to Parliament to deliver what they call the "Moko petition", which has received thousands of signatures.
The campaign, led by the Sensible Sentencing Trust, follows the sentencing of Tania Shailer, 26, and David Haerewa, 43, who were able to plead guilty to manslaughter despite being charged with the murder of Rotorua toddler Moko Rangitoheriri.
Shailer and Haerewa were supposed to be looking after 3-year-old Moko while his mother was in Starship Hospital with her eldest child.
Instead, the pair tortured the 3-year-old, kicking, stomping, slapping him, and rubbing his faeces in his face. He was pronounced dead on August 10 last year.
The pair were jailed for 17 years in June but have since filed an appeal over their sentence, the longest handed down for a charge of manslaughter. The appeal will be heard in Wellington on November 3.
As the pair were sentenced in the Rotorua High Court, organised marches and rallies were held around the country to protest the plea bargaining which saw the murder charge replaced with manslaughter.
At the time, Attorney-General Christopher Finlayson said the murder charge was dropped as there was a significant risk Moko's torturers wouldn't be convicted if they headed to trial on a murder charge.
Today campaigners carried a banner down Lambton Quay chanting "enough is enough".
The banner read: "justice for all, enough is enough."
Marchers held white crosses and appeared to be carrying a small white coffin.
Traffic followed behind the group of marchers, as they walked down the street, across three lanes.
About 40 or 50 people joined the march, chanting "justice for Moko" and "murder not manslaughter".
When the group reached Parliament House, they laid their banner at the base of the steps and placed their crosses on it.
NZ First MP Denis O'Rourke accepted the petition, which was carried in the white box, to the House of Representatives.
He said NZ First was looking into changes that could be made to the Criminal Procedure Act, including that juries always be given the opportunity to decide on alternative charges.