I saw it overhead Elstree heading roughly 300 deg at about 13.30 - It was certainly advertising EdF and it seemed (from the ground) to be above circuit height, but not hugely so. The banner looked very big and was very easy to read
Saw it a little later heading east (probably following the M25).
Perhaps someone should ask Elstree whether it spoke to them as it passed through their ATZ!
*Edited to remove reference to Blackpool*