Thanks for the help guys...it was not the answer I was hoping for but at least now I can plan properly.
So I got confused as it seems that if you have a CNI from the UK you have to convert this to a local CNI and then wait 10 days for the marriage license rather than 21 days when applying in Phil. For me it looks like the best plan will be to return to the UK get a CNI get as much organised in advance as possible and then come over for about 3 or 4 weeks to get married.
Thanks again
Steve