Why not ring around? BA/Midland etc. would gladly help you clear the R/W as it affects us just as badly re: Diversions and long slot delays.
The delay in the aircraft being towed from the runway was in fact that the Handling Agent who had 2 hours notice of the fact that the A340 would not be able to vacate could not get their act together !!!
Do BA not handle SA @ LHR ??? Sounds familiar if they could not find a tug!