"This funding proposal has created unprecedented concern - and unity - across the education sector. Educators see no benefits but great risks to education if global funding is to go ahead," said Green.
Roberts said the Government needed to take bulk funding off the table and focus on better ways to address inequity and chronic under-funding of the education system.
The unions would continue the campaign with the launch of a roadshow starting in main centres next term. The public would asked to sign postcards to the Minister of Education rejecting bulk funding and calling for better funding.
Acting Education Minister Anne Tolley said the unions had been involved in discussions around a new funding system "from a much earlier point than usual".
"Their feedback, alongside the views of teachers and principals that were gathered by the Ministry of Education will be taken into account when Minister Parata reports to Cabinet later this year. The Cabinet will then decide how to progress.
"Discussions on the funding review remain at a very early stage. No policy has been developed yet and nothing has been decided. More funding has not been ruled out.
"In fact, any changes won't be implemented until 2019 at the earliest. We want to take the time to get this right and for any changes to be better than the current complex system."