Thanks for the information and the PM.
It's a pulsing squeak as opposed to a constant sound and it's there when coasting, cornering, reversing, smooth or bumpy roads; all at slow speeds. I can't hear any sraping, just squeaking.
If it is the pads, I was going to change the front ones along with the discs anyway, so now could be the time.
I'll take the wheel off and have a proper look.