"P8" on 9th Jan
Another photo of "P8" showing the comparison with the Lesser Black Back in front. Clearly a lighter colour grey than the LBB (this time a Fuscus Graellsii) and darker than the Black headed gulls nearby - whichever angle the gull was at.
It is slightly larger than the LBB. From this shot and the previous one, we can probably rule it out as being a LBB (either a Graellsii or Intermedius)