The results on Google are very misleading, Strongy. Most of the images don't bear any relation to the actual plant and flowers, but your photo is spot on. This link is the only one I found to support the ID Shropshire Master Composters News: Comfrey - the wonder plant I grow the Bocking14 strain and it's identical to your photo. I've also got the yellow-flowered, low-growing one. A complete thug!
It looks like comfrey, should be a couple of foot tall, so a big robust plant. The only doubt I have is because mine is no where near flowering yet, perhaps it's milder with you Strongy.
100% Symphytum. Maybe Symphytum x hidcotense? Symphytum officinale x asperum x grandiflorum = S. 'Hidcote Blue' Hidcote Comfrey | NatureSpot UK Wildflowers - Boraginaceae - Symphytum X Hidcotense, Hidcote Comfrey Comfreys http://www.wildflowersofireland.net/plant_detail.php?id_flower=557&wildflower=Comfrey, Hidcote Hope this helps.
