Does anybody know anywhere I can get a couple metres of 20 core cable, at least 0.2mm2 (24AWG), either in the UK, or from somewhere that won't cost a fortune to get delivered to the UK.

I'd settle for 25 core, which is all I've found available by the metre so far (from Farnell, but it's on back order with estimated delivery mid September).
I don't really want to buy a reel, as I only need a couple metres, but all my searches have only brought up sources of full reels, and I don't really need 50metres..