Me and my mum are both Polish by birth however we have just received our British citizenship.
Good for you!
(btw, sorrry for that, but i was getting errors in posting)
We know the Polish government does not accept dual nationalities however my mum does not want to cancel as it takes to much hassle.
that's false. Polish government has no problems accepting dual (or multiple) citizenships of its citizens. However, in Poland, only Polish one matters.
My mum is married
(edited as quotes cannot be longer than 50 words)
if your mum got married (and change her surname) before being granted the citizenship, then it was her duty to change the name on Polish ID (by updating the birth certificate, and applying for new ID cards)- she couldn't change it here in the same way british citizens can (as she wasn't one back then).
ok, it would be easier if you could clarify few things:
1. How did your mum changed the name (I've assumed that because of the marriage- correct me if i'm wrong)?
2. When did she do it (before or after the marriage)? How did you do it (by registration as a british citizen or otherwise)?
Untill the (Polish) birth certificate is amended, the name is not changed in Poland, according to polish laws.
In UK one can change their name by executing the deed poll, no birth certificate changes are required.
And yeah, I've got naturalised as well, and as well i've changed my name (in PL and in UK).