Originally Posted by
corporate-wage-slave
Just out of interest, for the Original Poster, is this flight leaving exactly as booked in terms of timing? The impression you are giving is that you would not have normally booked something with such a short (albeit legal) connection time. If there have been changes to the timetable since your first email on the subject (on the day of booking) then you would have a case for ringing up and asking to be moved.
+1. If not, however, and it is just that the TA booked this as is, then it is unfortunately extremely unlikely that BA will allow the OP on the earlier flight without paying the full change costs and he is likely wasting his time going to the airport early (bar cases of delays known in advance but those are quite rare on short haul flights compared to delays that become apparent later down the line). In my view, the HAM lounge is not worth spending extra time at and I'd much rather stay home/at the hotel a bit longer before the long flight.