The Electoral Commission website says regarding UK citizens living abroad:
Who can register as an overseas voter?
If you are a UK citizen living abroad, you can apply to be an overseas voter.
You must have been registered to vote in the UK in the last 15 years and be eligible to vote in UK Parliamentary general elections and European Parliamentary elections.
If you were too young to register when you left the UK, you can still register as an overseas voter. You can do this if your parent or guardian was registered to vote in the UK, as long as you left the UK no more than 15 years ago.
Does this mean that one could live in the UK for a short while, then register, then be indefinitely registered after moving back abroad (EU) (Ie. one just needed to have registered within 15 years of leaving UK)?
Or does it mean that one could live here for a short while, register, then be registered to vote for the next 15 years (Ie. one can only vote in the UK within 15 years of leaving the UK)?