I panicked and on the Thursday before the Saturday, I got a National Express down to London, stood in a long queue at the Embassy, had lunch in Hyde Park (M&S sarnie & pop), then went back to Embassy. Hopped on a bus back home, got there midnight Thursday/Friday.
Midnight Friday/Saturday, got a coach to Gatwick for the flight to Cairo, delayed, missed the pyramids and museum, flight 10am to Luxor, FAB, then a wacky race to Hurghada under police escort. Everyone else diverted at Cairo airport to buy their visa, worked out cheaper than my trip and a lot less hassle and not so tiring.
Have fun!