Spouse Bringing Children- Parent Approval

[JustinS 44]

I know this is a question that may be best suited for a lawyer/solicitor but I'm hoping I can get an answer here. 

 

My spouse needs to get approval from her ex for the kids to move. We have a document drafted but are not sure about the next step. 

 

I found one instance online of someone saying that the embassy asked for this to be notarized, but I know notary in the UK is different than notary in the US.   Would this form being witnessed by a solicitor suffice or should we pay the fee and get a formal notary. 

 

Has anyone else done this?

[Wuozopo 4,294]

I have know several from the UK who had the consenting  parent sign in front of a solicitor and that worked for a London interview. 

[JustinS 44]

So as long as it is properly witnessed, not necessarily notarized?  I think we probably have one shot at getting the father to sign, so I don't want to get the signed form and then find out we need it notarized as opposed to witnessed.  Can anyone else confirm?