I've had this problem, and I've got the same engine as you.
Last time, it was the Fuel Pump Relay. Easy, just get one from the scrappy (I got mine from Dixons on Cleveland Street, they charged me a pound) or from Vauxhall (14 quid).
The next thing it could be the ignition coil. It's hard to check, because the coil is indirectly linked to the FPR, which is linked to the immobiliser. If you put a ammetre to the points, the coil flicks left and right as you turn her over (so if you put the ammetre probe on one of the coil points, it would go on-off-on-off), if only one works, it's the coil...
However, it could be down to the Coil Amp, which is under the coil (It's a 1 inch black thing that costs 140 quid new !!!). If your car starts in the morning, and doesn't when it's warm, this'll be the culprit, as a faulty one fails to operate when warmed up with a bit of voltage.