"The mānuka honey is different all around the country - we know that from genetics and all of that. So up here it's very low in 2-MAP.
"It could be that the chemical is water soluble and so in warm temperatures you get up north it could disappear from certain places. Honestly, we don't know what the real crux of the issue is," he said.
Craig said this meant even where bees have nothing but mānuka to feed on, the honey could be low in 2-MAP and therefore miss out on a mānuka honey classification.
This had a huge impact on beekeepers as top-grade manuka honey can fetch up to $70 per kg but if tests define it as non-manuka, the price drops to less than $20 per kg.
"It's financially crippling for some beekeepers. They struggle to make ends meet."
Pita Tipene, chairman of Tai Tokerau Miere, is calling for immediate consultation to establish an interim definition that is more acceptable to all beekeepers and international customers.
He said protecting the term mānuka and integrating Matauranga Māori, which had been completely ignored so far, into the process were key challenges to the industry.
The Mānuka Honey Appellation Society and MPI will be present at the hui which starts at 10.30am.