Opposition parties say there's no point in increasing the penalties for animal cruelty if there is no-one to enforce them.
National's Animal Welfare Amendment Bill would increase the maximum penalties for animal cruelty from three to five years imprisonment and double the maximum fine to $100,000.
It also adds the new offence of reckless ill-treatment of an animal, which would carry a maximum of three years in prison and a fine of $75,000.
The bill was originally drafted by the National MP for Tauranga, Simon Bridges.
He told the House that in the history of New Zealand fewer than 10 people have sent to prison for animal cruelty.
However, Labour and the Greens say there are only five full-time animal welfare investigators, which makes it difficult enough to enforce the current law.
Former Agriculture Minister Jim Anderton supports the proposed changes, but he told Parliament there's no point in increasing the penalty if there's noone there to investigate the crime.
But Agriculture Minister David Carter says more money has been freed up for frontline services and he's confident more prosecutions for animal cruelty will result from the legislation.