In case any one else has the same issue this turned out to be the rod coming adrift from the back of the external handle.
After removing the door card, drilling out the rivets and removing the plastic anti theft device you then have to remove the rear guide for the window. This is held in place by two hex screws. The guide also incorporates a cover that hides the rod between handle and lock so until it's removed you can't see it. The rod just pushed back into a plastic clip At tthe back of the door handle so then just a question of putting everything back. Acknowledgements to MEP for suggesting cable ties to fix the anti theft device back in place worked a treat.
After removing the door card, drilling out the rivets and removing the plastic anti theft device you then have to remove the rear guide for the window. This is held in place by two hex screws. The guide also incorporates a cover that hides the rod between handle and lock so until it's removed you can't see it. The rod just pushed back into a plastic clip At tthe back of the door handle so then just a question of putting everything back. Acknowledgements to MEP for suggesting cable ties to fix the anti theft device back in place worked a treat.
