Saw this in the Hayes, Middx branch. 500ml bottles of Gales* Seafarer ale for 88p each.
The bottled version is 4.2% versus the draught at 3.6%. Used to be a nice beer but not tasted it recently.
No restriction on number you can purchase. Not found on-line so I guess in-store only. Don't know if it's a nationwide offer or just a regional one.
* Since they bought out Gales and shut down the Horndean brewery, Gales is just another Fullers brand.