Ex spouse refuses to sign separation document

[ppreyes3]

My common law partner and I are from the Philippines. I’m a permanent resident here and we have been living together since July of last year. We are in the process of gathering documents and evidence. We have been legally married from the Philippines and since divorce is illegal we can only provide affidavit of separation. My ex and I are amicable, he has written a letter stating the fact that we have been separated. My partner’s ex refuses. Is an affidavit of separation sufficient for his case to prove they are separated? They also have 2 kids and she will probably refuse the medical examination for them. Any advice on what to do?

Thank you.