Might want to check the Ignition Coils too, I can see this thread is old, but if anyone else has this problem it might help out :)
It's relatively inexpensive (apart from the Engine Coil unit which is usually around 41.99euro + Labour charge approx 1 hour) to purchase or replace this unit.
It's possible that the coils or battery arent giving enough power to the Spark Plugs to ignite. You may have recently noticed higher fuel consumption and/or less acceleration than usual. One way to test if it is a coil is to ask your mechanic to look over or remove your spark plugs (replacing if necessary) as there may be a burnt residue on them due to the coil damage. Also, when a coil is gone, you may notice a higher concentrated odour of petrol from your exhaust. This is due to wastage of fuel which the car is trying to use to ignite the sparks.
Hope this helps anyway :)