Starting from 20th of April, 2023, all new applicants for a certificate of naturalisation are only required to provide a certified colour copy of the biometric page of their current in-date passport.
This copy must be certified by a solicitor, commissioner for oaths, peace commissioner or notary public.
However, the Department maintains the right to request for actual passports to be submitted as part of the verification process.
Please see full guidance notice here.