Music teacher unfairly 'asked to leave'

[supersop60]

I am a self-employed music teacher, working as a peripatetic in a school. One of my colleagues has been asked to leave by the (very new) head of department.
She has had a couple of complaints about her teaching methods - she is Russian and very strict - but instead of moving the students to another teacher, he has asked her to leave. She is brilliant at her job, gets excellent results, and does a lot for the school by way of accompanying concerts, exams etc.
My question is - do peri teachers have any rights? can the rest of us make a stand (protest) and keep our jobs?
Any experience of this or opinions?

What does your contract say? Did you issue the contract or did they?

There will be terms by which a contractor can be terminated.

Since we are self-employed, we have a visiting teachers' agreement, but no contract as such. The school issued the agreement, and I'm going to have a look at it now.