Unable to decipher the true meaning of...
"As soon as I make contact between the gas hob ignition plug to the circuit (earth pin)"
But no matter - you need an electrician - some quality bonding may be called for - and if the "I make contact" means you actually touching something - with your hands - then you may be in danger - stop making contact immediately and isolate the hob.
Take care...
Peccavi
August 2009