Well it's fixed now. I have to say that my good friend Dave, aka
greenVFR, deserves a great deal of credit and another HUGE thank you from me.
Within 20 minutes of us getting the bike of the recovery truck it was on the ramp in his workshop with the tank off and the fault was pretty much diagnosed.
Further research on the 'net last night and today confirmed that it was a known fault for which there had been a recall. However, my dealer said that my frame no. was not within the range of the recall.....
The fact that the dealership keeps the DM controller for the fuel pump as a stock item is pretty telling though. £50 later for a new DM controller and the bike's back together and running, although we haven't had a chance to road test it.
The service guy in the dealership has also submitted a warranty claim to BMW for the part, in spite of the fact that the bike's 6 months out of warranty.