It would appear from some of the responses here, such as...
"In extremis I think you could be abeam Lajes with trip fuel to LGW, no holding capability and no div fuel (just min reserves) and still be legal."
...that we have truly found the problem with the low fuel state that permeates the operations of some British operators.
The absence of other carriers (Malaysian and Qantas, years ago, excepted) seems to indicate a planned modus operandi on the part of some British carriers to the idea of....'we can get away with it because the CAA will somehow 'understand' and further, possible expedited handling by a 'co-operative' ATC.