The plug spanner itself is fine as it undid the remaining three plugs without difficulty, the hex on the rogue plug is intact also as I've peered down the tube with a torch and fished around 'flexible claw spring loaded grabber thing' (technical description - not) and I can definately rotate the...
Changing the plugs recently, one plug is just 'spinning' in its threads - will not tighten or indeed loosen any more than it already is to remove it.
As the plugs are recessed in the 'tubes' this is creating a bigg issue for removal.
Are the 'tubes' an integral part of the cylinder head or...