Thank you gents for your interest and positive suggestions. Ralph I tested the fuel pump as you suggested and it works fine. I didn't realize that using a blow through pipe to clear the fuel line would take such little puff. The resultant bubbles were followed by a surge of fuel through the fuel tap, the cork seal having decided to be part of the action didn't hold back the fuel in the closed position. Lifting the front of the car stopped the flow so now I will replace the cork seal or look at alternatives as these seals tend to shrink with inaction. Again thank you all for your help.