Education Minister Chris Hipkins admits to being taken aback by a newspaper advertisement placed by 40 Auckland principals critical of the government's review of NCEA.
The government is reviewing the way the system is run, organised and funded.
In an open letter in today's Sunday Star-Times and Herald on Sunday, the principals criticise the lack of consultation; complain that the four-month timeframe is too short; and question whether the government is really committed to a review of NCEA when it's just one of 13 education reviews.
Mr Hipkins said he was disappointed and surprised by the letter but said it was early days and people needed to give the process a chance.
He said he had discussions with several of those who signed the letter.
"They don't represent the views of all principals and teachers around the country.
"But actually that's why we're a genuinely open consultation exercise, we want to hear from everybody who's got a view, including those whose voices aren't always loudly heard."
But National's leader, Simon Bridges, says the Government's being arrogant and dismissive.
"When you've got that many people saying that to you, then maybe you need to reset, you need to front and you do need to listen and take what they're saying seriously."
Changes possible under the review include scrapping level one exams and halving the number of credits needed to pass the first year.