Mat leave and handing in notice

[BlackeyedPetitsPois]

Currently on mat leave (only 2 months in) and have told employer that I intend to take the full 52 weeks. I am able to alter this by giving 8 weeks notice however. All ok with that.

I am going to be looking for a new job whilst on mat leave. I do however want to take advantage of my mat benefits etc with current employer as I've been there over 12 years.

I will have accrued substantial annual leave by the time I am due to return to work, which I intend to tag on the end of my mat leave.

My question is this: do I have to return to work ie:be physically in the office, before I hand in my notice or can I do it whilst on annual leave (the bit I'll be tagging onto the end of my mat leave) and use ann leave to work out my notice period?
Cheers.

[CurlsLDN]

I handed my notice in about six weeks before I was due to finish my year. I'm sure you can work it out on annual leave, as you are still employed throughout mat leave and annual leave