Sounds like the relay for the heater plugs has gone. I had the same problem
with my 205 K reg Diesel Turbo, replaced relay from scrapyard at a cost of
£10 and been fine since.

What you can do to check that this is the problem is connect a jump lead
from the battery + to any of the glow plugs, ensuring it touches the metal
part. Watch out for sparks when you connect and re-connect, nothing serious
just a little arcing sometimes. If the engine does start, then disconnect
the lead to stop it running the plugs still.
If it does start then means it's definitley the relay.