A primary school principal who likened Education Minister Anne Tolley to Adolf Hitler has apologised for bringing her school into disrepute - but has stopped short of apologising to Mrs Tolley.

Mrs Tolley has refused to respond to the Nazi reference by principal Marlene Campbell, but her spokesman said Ms Campbell "appears to be trying to justify her highly offensive comments".

Ms Campbell, principal of Invercargill's Salford School, said the comments she made on her Facebook page last week were "ill considered". But she is not backing down in her opposition to National Standards, which she calls one of the "most divisive" policies for schools.

Ms Campbell wrote: "And the MOE attack schools deferring setting targets, that's a constructive response? Excuse me, Minister Hitler? Am I in Germany? Is this the end of self-managing schools?"

Yesterday, in a statement posted on a school website, Ms Campbell said she regretted the "not thought through reference to Nazi Germany".

"I unreservedly apologise to the parents and students of Salford for casting our school into disrepute.

"I feel passionately about National Standards and I am immensely frustrated by the damage they will do to children's learning. I really regret that my comments have created a diversion from the real issues: the negative impacts of National Standards as a policy."

Mrs Tolley's spokesperson noted that Ms Campbell "has yet to apologise to Mrs Tolley".

The Salford School Board Of Trustees said the comments by Ms Campbell were her own, and not the views of the board.

"We have met with Marlene to discuss these inappropriate comments and she has provided us with her written response.

"As a board of trustees, we wish to continue to work together to ensure our children strive towards educational excellence."