Starting problems

Our Espace 1988 TXEi will not start using the ignition key but the engine will turn over. It will start if you bump start it.
I have done some basic checks and there is no spark at the plug when the engine is turning over using the ignition key. It will start with the ignition key once the engine is hot. I have a brand new battery on it and I have tried to jump start it using a diesel battery but still no joy.Anyone any ideas of what the problem could be ? :confused:

I have Fixed it. Yes, it was the TDC sensor it took me 3hrs to fit as it was at the back of the bell housing but now it starts first time every time ;-)