Form ID3

Dear HMLR, I am executor of my late spouse's estate.  I am a UK permanent resident but do not hold a UK passport.  How do I submit form ID3 in support of form AP1, as there is a specification that a full UK passport is required?  If this is not acceptable, what other option is recommended?  Thank you. 

D C - if you don;t have a UK passport then you will need to use form ID1/conveyancer to have your identity verified. Form ID1 offers alternatives to a passport