Can my contract change?

[youknowyourself]

I'm a teacher and I've just returned to work after mat leave. I will be returning on a 0.8 contract as agreed (I have the corrisponding paperwork etc).
My headteacher informed me that he fully expected me to return to full time hours in Sept and should he put it in writing now?
Of course I have said no but where do I stand legally?

Oh bother, this should have gone in employment issues.

Thanks for responding. I've never actually seen a copy of my contract as teaching works on verbal agreement.
They've been evasive about handing one over previously.

Look for a unilateral variation clause. It means they can change the terms without your consent. If it's not in the contract then they can't enforce it and of course you're not bound by it.

If you are classed as and treated as an employee, you will have a contract of employment. Who pays your NI contributions? Or are you on a zero hours contract? The maternity leave implies you are en employee and you should ask to see your contract.