No.

CNI is no longer required by the UK citizen for marriage in the Philippines. When you go to the British Embassy in Manilla, they give you a letter to explain to the place you apply for the marriage licence that it is no longer required.

For my marriage in Cebu I needed:

1) CENONAR (plus two xerox copies)
2) Passport with entry stamp (two copies of Each)
3) Affidavit to marry (plus 3 copies)
4) Certificate of Attendance at a pre-marriage seminar

If you had a previous marriage, you also need your decree absolute/annulment and copies or, if a widow, proof of this.

For the affidavit to marry you need Birth Certificate and Passport. You need to prepare the affidavit from the template on the Embassy website and swear it holding a bible after paying the fee.

Hope this helps. Just been through this.