Mana Movement leader Hone Harawira says Treasury advice which suggests the food in schools programme does not work is ridiculous.
In a report to the Government early last year, the Treasury said it had doubts that the food in schools programme would do anything to improve children's learning.
The Children's Commissioner's Expert Advisory Group has recommended such a programme be introduced.
Hone Harawira, who was behind the Feed the Kids bill, said he was not about to listen to a group who he said was trying to please the Government.
Mr Harawira said the Treasury was looking for answers to suggest why the programme should not happen, when in fact it should happen because the experts, such as doctors and teachers, said it should.
Mr Harawira is urging the Treasury to go without breakfast as well as lunch for a month.