It's not just principals, unions and the Opposition who are furious - his own party candidates and former MPs are ordering him to fix it.
Not one, or two, but four former Green Party MPs couldn't hit social media fast enough to blast their party for backing taxpayer-funding of a private school in coastal Ōakura.
Sue Bradford described the move as incredible, and a total hand-out to the wealthy.
Mojo Mathers took to Twitter to say she was furious, while Denise Roche warned the party's credibility was being ruined by such a move.
Catherine Delahunty, who was a Green MP for nine years - holding the education portfolio for many of them - says she's astonished.
"This is a mistake, fix the mistake and the electorate will respect you for it. Don't fix it and they will lose faith in you, it's that simple."
Kealy Warren, acting principal of Marfell Community School - a low decile school in nearby New Plymouth, couldn't believe the news.
"I felt physically sick, I wanted to vomit. I could not believe we were being so disrespected in favour of an elitist private school."
She says it sent a message of worthlessness to her students.
"I'm heartbroken for our beautiful children that have been told yet again you're the bottom of the heap stay there - what are you going to amount to?
"You're the bottom of the heap, just stay there, you're not going to add to the economy when you grow up so sit there in your leaky classroom," she said.
The Green Party co-leaders James Shaw and Marama Davidson are in damage control and are holding an online meeting tonight with frustrated and disappointed party members.
High-profile candidate Ricardo Menendez March is one of those, and has already gone public with his criticism.
He says candidates are free to say when they disagree, and giving millions to a private school in Taranaki doesn't align with the party's policy.
Shaw says he knows the state of public schools is not good enough, but the Government has allocated almost $2 billion towards fixing them - the money just hasn't reached most of them.
"This is an area I think that New Zealand should be frankly ashamed of in terms of our continuing underinvestment in this area."
Shaw says it's not true to say the Greens have abandoned their policy to not publicly fund private schools.
"Well that is our policy and this money doesn't go into the operations."
Asked if he was being acute, Shaw replied, "there's a balance of objectives we're trying to achieve here - remember that we are going through an unprecedented time with Covid-19".
It's just a building, he says.
"In terms of the infrastructure spend, it is in many ways just another construction project."
Even Education Minister Chris Hipkins was ducking for cover when asked about it.
"It's not necessarily a project I would have prioritised. That was something the Green Party advocated quite strongly for.
"It was one of their wins, if you like, out of the shovel-ready project area, and so that's a question for them."
So did Shaw even consult with his own caucus before making such a controversial decision?
"Well it was under Budget secrecy, so whilst something is under Budget secrecy ministers can't talk beyond other ministers about that."
He was the only Green Party MP that knew about it and agreed to it.
As for the National Party, education spokesperson Nicola Willis says it's a joke.
Shaw might find she's not alone in that opinion when he finally consults with his party later tonight.
