Ford Mondeo Remote key unlocks and locks but wont start engine?

1998 R-Reg Ford Mondeo. Remote key unlocks and locks but wont start engine.

I will explain i brought my car a couple of weeks ago, since i've had it it has never locked or unlocked from the remote key, although today i notice the air bag light was flashing so i checked on the fuses pulling one out at a time, Its very strange as now it unlocks and locks but will not start the engine.

I have one problem this is the only key i have for vehicle...

Please can someone help me i have tried disconnecting the battery but that hasn't worked.