I used to give anyone like that (govt.depts) my parents' address in the UK.
I'm pretty sure they don't bother to check any of your UK details anyway....until they need somewhere to send the bill for your funeral.
When I went to live in the Phils for a few years I also arranged for my dad to have power of attorney in my absence.
I've also been lucky in having a brother high up in the FCO, so (hopefully) he'd have helped me out if needed.
