There's only 2 flights that day LHR-GOT, but the first leaves at 0620 so way too early for anyone flying into LHR to connect onto. As such, anyone connecting in LHR to GOT that day has to to take the later flight. It's a 319 with less than 140 seats, so it's not hard to see why it's fully booked already. If you're lucky, BA might upgauge it to a 320.

It's a real shame they don't operate the nightstopping service anymore - clearly there's a lot of demand.