"The Registrar General can give no assurance that the divorce would be recognised as valid by the Courts of the Country or elsewhere".
This is the first time i have known a statement like this.
The Registrar General should know that there are countries that doesn't have divorce. Ex. the Phils we have the annulment instead. So when you submit your paper to the county where you intend to have the civil wedding they will send your paper to their H.O. to confirm what is the equivalent of that to their country as every country has different laws.
Your fiancee is annuled in the Phils so when she register here in the UK she should use the status "single".
Best of luck Ady.