School principals came in for a caning this week from KwaZulu-Natal premier Zweli Mkhize and his MEC for Education, Senzo Mchunu.
Mkhize blasted principals who consult their union first before complying with instructions, saying the "moral" commitment to pupils should outweigh any other issue.
And, Mkhize said, he fully supported Mchunu's remarks about some school principals being like "jellyfish".
Taking a swipe at the SA Democratic Teachers' Union (Sadtu), Mkhize said the issue of professionalism among teachers should be dealt with, including the role of "what we may call a revolutionary trade union".
Speaking to the Sunday Times at the basic education conference in Durban this week, he said: "The role should be about saying that education is at the centre of social change. The issue of supervision of teachers needs to be strengthened ... but also the protection of education so that it's not subjected to any form of disruption."
Mkhize said strong trade unions were good, but a social compact was needed that said "nothing will interrupt or interfere with the education programme of every learner".
"Everybody must say that whatever legal contracts we have between us and any parties are less important than the moral and spiritual commitment we have."
The provincial government had demanded from headmasters a "24-hour commitment and absolute loyalty to managing the school".
Mkhize said: "Nothing of his or her activities should come in the way of his commitment. You can't suddenly change what is correct for the management of the school simply because you have been persuaded by the union of which you are a member."
Mchunu said principals "must listen to one boss".
He said a number of schools were not functioning properly because of weak leadership.
"We are saying to principals, 'you have to ... face up to the challenge. If you are jellyfish, you have no backbone and you have no place here'."
Sadtu deputy general secretary, Nkosana Dolopi, said the union was committed to quality teaching. "We won't stand in the way of principals to manage their schools."