A further 15 schools have signed up to join a coalition criticising the Government's review of NCEA.
The group of now 70 principals, dubbed the NCEA Coalition, have called for the review of NCEA to be halted.
They described the consultation process as "bizarre", putting the views of children ahead of professional educators and lacking proper consultation with school leaders and teachers.
Glen Denham, principal of West Auckland's Massey High School, said the coalition had made some progress over the past couple of days with some dialogue occurring behind the scenes with the Government.
"We are hopeful of some positive developments early next week. Until then, we will not be publicly commenting further."