Products labelled "free range" would have to meet mandatory standards under Green Party policy announced today.
Greens leader James Shaw said that would mean free range "means what it says", and his party's policy would also require country of origin labelling to single ingredient foods such as fruit, vegetables, meat, fish, grains and oils.
The policy comes after controversy over free range labelling, including allegations a major egg supplier was wrongly labelling cage eggs as free range.
In releasing their plan, the Greens said conditions vary hugely between producers, with many "free range" eggs coming from hens that don't get to spend time outside.
"We all have a right to know where our food comes from and under what conditions it was produced," Shaw said.
"We will fix the wild west of free range labelling by requiring food producers to reveal information about their animal welfare standards."
Shaw said there was no current proper standard for what can be labelled as free range.
On country of origin labelling, Shaw said under the current system it could be difficult to tell if food was made in New Zealand. For example, pork can be imported and made into ham or bacon and be labelled as product of New Zealand.
"Some of our biggest trading partners like Australia already have country of origin labelling. It's time that New Zealand caught up."
The policy would require a mandatory consumer information standard for free range to be developed under the Fair Trading Act.
The Greens say that would require producers that label their food free range to disclose information about animal welfare standards.
In March, Primary Industries Minister Nathan Guy said a national, legally binding definition of free range may have to be created. Guy made his comments after a major supermarket supplier was found to be passing off caged eggs as free range.
Australia last year created a legally binding, national definition for free range. Hens must have "regular and meaningful" access to the outdoors, and the density of chickens outdoors must be no greater than one hen per square metre.
In New Zealand, there is a code of welfare for layer hens which includes minimum standards, but the standards are not prescriptive and there are no penalties for non-compliance.