meaning of UK public authority

[theuniverse]

Hi everyone,
We want to get a new EU passport for our son, but the local embassy wants either both parents to be present or if only one can come, a written authorization from the other parent certified by a UK public authority. Can anyone clarify what is meant by "public authority" and where could I certify the authorization paper for free( except the embassy itself)? Thanks.

[CoolGirl1984]

Hi everyone,
We want to get a new EU passport for our son, but the local embassy wants either both parents to be present or if only one can come, a written authorization from the other parent certified by a UK public authority. Can anyone clarify what is meant by "public authority" and where could I certify the authorization paper for free( except the embassy itself)? Thanks.

As far as I know, police or any council office...