I've been told I can't return to my job, despite it still existing

[katypot]

hi
hope someone may be able to help. Just days before my official return to work after a year's maternity leave, (I'm currently on pre-arranged annual leave) out of the blue, my manager first asked and i'm now being told I can't return to my existing job (which still exists). I've been told I have to cover the maternity leave of someone else (same job title, but a very different role.) My job will be covered by someone else. I had agreed my return date with my manager many months ago and that it would be part-time and there was no problem with this. I'm just wondering if anyone can help me with where I stand legally. They say they can force me into another role because legislation allows this as I've taken more than 9 months maternity leave. While this is the case, nowhere in the company's maternity policy is this stated, neither was it mentioned in any of the correspondence I received in the run up to my leave and it wasn't mentioned when I advised them I was planning to take a year. I would presume this should have been made clear to me.
If anyone can advise on where I stand. I'll be very grateful.
thanks

From the www.direct.gov.uk/en/Parents/Moneyandworkentitlements/WorkAndFamilies/DG_065153 website:

"When you return to work after ordinary maternity leave, you have a right to the same job and the same terms and conditions as if you hadn?t been absent.
This also applies when you come back after additional maternity leave, unless your employer shows that it?s not reasonably practicable for them to take you back in your original job (for example, because the job no longer exists). In that case, you must be offered alternative work with terms and conditions as if you hadn?t been absent."

They are in the wrong whatever their policy states...

It is true that if you take the full 52 weeks leave instead of 39 then you lose the automatic right to your old job but this doesn't mean they can necessarily force this on you. If you had an agreement that you would take 52 weeks then return to your old job this could be deemed a contractual liability.
It sounds like you suspect they are trying to bend the rules to get rid of you because oof your maternity leave. This is discrimination and is illegal but is very very difficult to prove at a tribunal. I would suggest you make an appointment with someone experienced in this field.
You will need evidence to back you up so try to get this from colleagues etc before your employer.
Good luck.

Thanks for your advice. I really appreciate your help and hopefully I may get a satisfactory resolution.