Z3 immobiliser

this has probably been asked about before, but my 98 z3 wont start, the alarm arms and disarms, the dash lights up, but nothing, no clicks or anything. I can only assume its the immobiliserr, my remote is seperate from the key, I spoke to sytners in Nottingham all they said was get it in here and we'll look at it, but at £100 pounds an hour that has got to be the final step. any help would be really appreciated. thanks,

Even though the dash lights up, the battery is still the most likely culprit. Have you tried jumpstarting?

yes, at the moment its at a garage for its mot, the battery went flat overnight so the've had their booster/jumper on it,