Nettle-leaved Bellflower, is quite an impressive plant, growing up to 100cm tall and with large bluish purple bell shaped flowers topping it off. This is a plant that is sold by many wild flower seed and plant suppliers, because it is quite imposing and rivals many cultivated or garden plants. The Wild Flower shop is one such establishment which stocks it. The plant is native but with so many nurseries stocking it then garden escapes are always possible.
I think I have seen this plant growing in England but am not 100% sure, all the photos here are from plants growing in France where I see it quite often. Here is a closer view of an individual flower.
According to the BSBI it is only recorded in 555 tetrads out of 2810, so not that common and also found mostly in southern regions. but records do extend into Scotland.
It likes shady places and will grow under fairly dense woodland, but I have also seen it growing in hedgerows in France where it is quite bright. It is a plant that likes the soil rich, dryish and also neutral to alkaline.
Finally one last photo which again was taken in France at a place called Zoodyssee which is a zoo and a very good one, it only has European species, but that includes Wolf, Lynx, Bison, Ibex, Harvest mice, and even a selection of snakes and lizards from the area.