National MP Allan Peachey has come under increasing pressure to make a more substantial apology for the "knife in your back" comment he made to a high school principal.
The Post-Primary Teachers Association described the comment, made in an email to Selwyn College co-principal Carol White, as "unprovoked, malicious, unethical
and inexcusable".
Education Minister Steve Maharey said the new Tamaki MP had apologised for being caught, not for being wrong.
Mr Peachey did not return calls last night, but previously told the Herald the message was sent by mistake and he had apologised. He said he didn't mean anything by the comment.
But the Herald understands there has been a history of tension between Mr Peachey and Ms White.
It is understood Mr Peachey spoke to a parents meeting at a Selwyn College feeder primary school and made disparaging remarks about Selwyn.
The college wrote a letter of complaint. Sources have told the Herald that Mr Peachey dismissed the complaint by returning it.
A National Party spokesman said last night that Mr Peachey, the former principal of Rangitoto College, had apologised and that was the end of the matter.
But PPTA president Debbie Te Whaiti said the apology did not go far enough and the threat raised questions about Mr Peachey's suitability as a National Party education spokesman.
"It is unacceptable for a politician to threaten a public servant," said Ms Te Whaiti.
"It is also representative of the kind of bullying behaviour that educators are striving to eliminate in our schools."
Students were routinely suspended and excluded for threatening other students and teachers and Mr Peachey "appeared to be driven by a personal vendetta and ideological differences with the school's management".
Mr Maharey said Mr Peachey should explain the comment and assure the college that its future would be secure if he were a minister in a future government.
Selwyn College adopts a liberal and inclusive approach to schooling and has adapted to meet the needs of its diverse community. That philosophy puts it at the opposite end of the spectrum from Mr Peachey's politics.
The comment from the first-term MP was a postscript on an email where he wrote: "P.S. Yes, I do have a knife in your back, so be careful!"
John Hinchcliff, chairman of Selwyn's board, said Mr Peachey should visit the school to "discuss what Selwyn College stands for and discuss any concerns he may have".
