if you have been offered an interview with another employer, do you let your current employer know? (there's nothing on the recruitment procedure to say that they'll take up references prior to interview).
As far as I can see:
Arguments for - it'd be polite and honest to do so; it's for a job in a different part of the country so it's not like it's a direct competitor; i have a good relationship with my current employer and would like a good reference to take away; i've not been applying for *loads* of jobs - this is the first in two years.
Arguments against - it might cause unnecessary panic; it might bugger-up future prospects at work if they thought i was looking for work elsewhere; the conversation will probs be pretty awkward.
What do you think, hive mind of DiS?