Notice period in a temporary job

Unwell2023

We still haven't been told anything, I would be slightly annoyed if they use my operation as a excuse in not saying anything as I feel under massive pressure to return to work 24 hours after surgery. A redundancy in another team has been announced under 'a need to reduce our overhead costs' and a goodbye on a week's (!!) notice. 

I got in touch with the new employer to explain and they seem accepting at the moment that I'm honouring a contract until 31st March.  

Can I check, say I give notice mid-March, am I then held to the notice period of one month? Of course if someone did try and speak about an extension sooner I'd come out with I'm sorted elsewhere.