Clear vegan and vegetarian food labelling should be put into legislation so consumers can be confident that what they are buying really meets their dietary requirements, say NZ's vegetarian and vegan societies.

The NZ Vegetarian Society and the Vegan Society of Aotearoa NZ today handed over their 'Ensure Accurate Labelling of Vegetarian and Vegan Products' petition to Green MP Steve Abel, whose portfolio includes food safety.

There was no definition of vegan or vegetarian in the Food Standards Australia New Zealand Code, and food producers were not required to identify if products were vegetarian or vegan.

The Vegetarian Society said misleading and unclear labelling practices were widespread, and led to consumer confusion.

"By advocating for clear, standardised, and enforceable labelling regulations, we aim to eliminate ambiguity and ensure transparency in the labelling of vegetarian, and vegan products," said Vegetarian Society spokesperson Ina Babic.

Babic said the term 'vegetarian' should be reserved for products that contain no meat, poultry, fish, or seafood, and that any use of animal by-products (such as gelatine, rennet, or certain colourants) should also be clearly indicated.

The Vegan Society said consumers deserved to know what they were buying without having to resort to reading every item on the ingredients label.

Vegan Society spokesperson Claire Insley said they wanted to help consumers make ethical choices simply and easily.

"If a product is labelled as 'vegan' or 'plant-based', then there should be no animal products or by products in the food," Insley said.

"All too often foods that have these labels are then found to contain milk solids or honey."

That presented challenges for both those making ethical choices as well as those with allergies such as dairy.

Insley said no other country had a legal definition for vegan and vegetarian, so if New Zealand did define the terms in legislation, it would be a world first.

Green MP Steve Abel said the Greens would do what they could to advance the petition.

"Increasingly as people make dietary choices around wanting to not consume animal products, it's very important that they have access to accurate information about what food products contain," said Abel.

"So we very much support the call for there to be effective and meaningful labelling for those who want to be certain that they are consuming vegan or vegetarian products."