At lunchtime my daughter comes in from the garage to tell me that there is a stong smell of gas so I go out and find a large puddle under the car (needless to say I did not bother to take some flash pictures of the spillage). After removing the engine, I had capped the gas lines with duct tape ... but then I closed the gas cap. Bad idea! As things heated up the next morning the air in the gas tank expanded and pushed the gas in the lines out past the duct tape :(
So now the car is sitting with the gas cap loose to prevent pressure build up in the tank and the gas lines are capped with silicon sealant "just in case". Fortunately it's meant to be cool all week ... but it looks like I'll definitely be pulling the gas tank next weekend.