Lost expired passport

Hi,

I'm a UK citizen applying for citizenship by naturalisation (5 years residency in Ireland). My current British passport is valid from 2017. Despite turning my house upside-down, I have absolutely no idea where my expired previous one covering the first two years of my residency in Ireland has ended up. There's a possibility I threw it away but I don't think I did... but that doesn't change the fact that I don't have it to send in with my application.

Has anyone been in this position, or know whether it is likely to cause problems with my application? I'm concerned that they may need the expired passport as evidence that I have been an EU citizen for the full five years (I wasn't born in the EU).

Thanks for any advice.

You cannot do anything else if you have lost your passport. Send an explanation that you have lost the passport and send a copy of your British naturalisation certificate

I guess its less of a concern for you as a British, as British passports don’t get stamped anywhere when a British citizen enters Ireland.

Your proof of residence relies on bank statements, utility bills, tax documents, employment letters etc.