Harding last year had his appeal against sentence dismissed by the Court of Appeal and today had his case called in the Supreme Court in Wellington in a final bid for a shorter sentence.
He is not the only meth dealer appealing in the Supreme Court today - unrelated offender William Allan Berkland's appeal against his own sentence of 13 years and three months in prison is being heard alongside Harding's.
Both appeals, while relating to completely separate offending, draw on Zhang v R, a Court of Appeal sentencing guideline judgment for meth offending.
Berkland was the "right-hand man" in a Wellington-based drug ring, in which more than $5 million worth of meth exchanged hands.
He earlier pleaded guilty to a range of charges, including supplying and conspiring to deal meth, as well as possession of and dealing other drugs, and possession of weapons and ammunition.
In court today, his lawyer Letizea Ord said Berkland was "not a sophisticated offender" and wasn't the mastermind behind the crime, but rather the "sidekick".
She said his co-offender, Steven Albert Blance, was the ringleader. Blance was the one with a heavily fortified property, CCTV and drone surveillance, and electronic sensor beams.
She said Blance organised the contact with the suppliers in Auckland and was the one who received more than 700 visitors during the time police were monitoring his property.
Meanwhile Berkland had a significantly reduced role and his sentence should have reflected lower culpability and involvement, she argued.
The "clear evidence of his addiction" should also have more of an impact.
The focus of both appeals relates to the offender's role in the offending, the link between the offending and the offender's addiction or history of deprivation, and the imposition of minimum periods of imprisonment.
