Paul... During my 23 years in Heathrow Tower I encountered many, many pilots who felt similarly hard-done by. Problem is that YOU and THEY didn't know the overall picture; the only people who do work in that tall building in the middle. Maybe you could have physically got out there but maybe everyone else at the hold was just about going to make their slot so if you jumped the queue a dozen other a/c might have missed theirs. You also have no idea how many other aircraft are starting with similar or earlier slots, or how many there are in queue.. Depending on the runway 1434 to 1449 would have been tight in the days I was there when traffic was less - on easterlies I would probably not have approved start-up unless you were on the J or K stands, for example.... and you say there was a runway change in progress! No way Jose!!