1996 Renault Megane starting problem

Hi I have a 1996 renault megane 1.6 which has developed a problem when starting. On trying to start the car all the dashboard lights/displays come on as usual but when turning the key nothing happens ( immobiliser is off) I will take the key out and try again and often it will start 1st time - other times it will take upwards of ten turns of the key to get it to fire up. So far I have replaced the battery, checked all the earths, replaced the tdc sensor and put a new female spade connector on the starter trigger wire.I am at the point where I am about to take a large blunt object to it - any ideas hugely appreciated
cheers Paul