I agree with David about the' seed potatoes' being grown at a high altitude
to prevent blight etc, but last year had a few new potatoes that had
sprouted and past their best for eating, so rather than waste them I
planted them and had a reasonable crop with no problems, so it's worth a
try; although for my plot of new potatoes next year I will still use
certified ones.

I forgot to add that I planted the uncertified ones well away from anything
else, as we're lucky to have a large garden.
Ros