If you turn the oven off does the sparking stop?
Ok so is it all the spark leads that are sparking all the time or just the oven?
Ok its all that's sparking then its proberbly a fault on the spark generator box at the back.
To be honest when you get a fault like this on gas ovens were all the burners are sparking all the time its usually the spark box at fault.
What you can try first is give the spark lead inside the oven a clean.
If you are able to do this yourself then remove the rear panel and then from there take the spark lead out from the oven and check it and make sure its not broken along the wire so its touching the metal work in there.
If the spark lead looks ok then im afraid its looking like the spark box at fault here and it will need to be replaced to cure this.
The spark generator is working normally from the manual button and it normally turns all igniters on when the oven knob is turned on. It would then normally turn off after the burner has lit.
The only thing that makes these spark is the spark generator. When you press the button on the front it sends a signal to the box to start sparking.
So when you let go of the button it will stop.
It wont be that button otherwise it will spark all the time even when its turned off.
So either a spark lead it touching the earth or the box itself is faulty then that's what causes it to spark all the time.
Check it out if you can and see what you find. The spark box will be located at the back usually at the bottom.