Self employed work while receiving mat leave pay

[Orangepen13]

Im currently on mat leave from my job in the NHS. I used to do a bit of private work on the side , self employed.

What are the rules around doing self employed work whilst:
a) in receipt of occupational maternity pay
b) in receipt of annual leave?

Don't want to be accidentally fraudulent!

Both absolutely fine to do, the OMP and annual leave are irrelevant anyway as they're contractual benefits, as long as you're getting SMP and not MA that's also fine too.

Assuming your employer knows you're doing the self-employed work/your contract allows it without notification - if not then there's breach of contract potentially, but that would be the case regardless of whether you were on maternity leave/annual leave or not.