Went to start the car again, and it wouldn't fire again.

Found I didn't put the relay back in properly :S my bad.
... but I took it out anyway to get the part number, which by the looks of things is different to yours safechav.

I phoned LSUK with the part number, and they had 1 in stock and were closing in 30mins from when I phoned ... RUN !!!
My 'rents popped into Ford as they were near it, and the guy at the counter said "well, theres so many bits on these cars I dont know where to start ... do you have the part number?" er, NO ! thats what I wanted to know.

So hopefully, I know have a replacement relay, and a newly soldered one as spare.