New job in the same company while pregnant

[MammaZ1]

Hi All!
I am writing as I need a little bit of advise.
I m currently in middle of pregnacy. I had applied for different role with my current employer and been successful. The job has got better salary+have some other benefits. Today I did get the contract to sign and it's starts in 2021- after my maternity leave. Before I had my contract I spoke with my future boss and agreed to stay in my current role up to maternity leave.
My question is- can my employer delay the new contract until my return back to work? It doesn't feel right, but I am not sure if they can do it anyway.
Thanks

No. That’s direct sex discrimination.

I think you've muddied the waters by saying you'll stay in your current role until maternity leave. They might have understood that to mean you wanted to start the new role when you return and the contract you've received reflects that. Wouldn't it be easier to start before maternity if you're only half way through pregnancy ?