Acanthus mollis, also known as bear's breech. You can see it here in the middle to the right of the "purple smoke bush", well it will be a smoke bush when it grows up.
I first noticed this plant years ago whilst walking in Newbury, near Victoria park, it was part of the planting scheme, I pinched a few seeds and unsuccessfully tried to plant them. Years later I tried growing them in the last house but for whatever reason they always disappeared, I blamed the snails.
So now having a bigger garden I have decided to grow them again, they have such a fantastic architectural shape and today on Facebook there has been a huge debate about wether to have them growing in the borders as it has been said that once you've planted them you'll never get rid of them.