The man who was the inspiration for the Government's education reforms says National should have stuck to its guns.
Plans for teacher cuts sparked protests across the country and a major backlash that forced the Government into an embarrassing U-turn earlier this week.
However, education expert John Hattie says increasing class sizes has little impact on learning outcomes.
Earlier today, Hattie told reporter Shane Taurima in an interview for TV ONE's Q+A programme that he thinks the Government should not have backed down.
"It's a mistake obviously in how it was handled, in putting class size right up front.
"If they had kept to the staff-student ratio they'd be more specific about the investment in the teachers."
Hattie said the Government will have to find another way to save money to pay for better teacher quality.