shuddering when letting off throttle

Hi chaps, strange fault has developed on the p38, its a diesel manual box, when you let off the throttle im getting vibration through the car seems like its related to the drivetrain as its a steady shudder rather than a fast vibration, im guessing its the U/J's on the prop shaft, would this cause these symptoms? Not sure if this is a way to test this but if you apply the handbrake when the car is still moving a little it bounces backwards and forwards 3 or 4 times, im assuming due to slop in the drivetrain?
any advice appreciated.
Josh

Looks to be a U/J so not too bad really, lets hope it lasts till saturday.

check the gearbox mounts are tight as well.

It will be one of the UJ's. Mine did the same. Front Prop shaft UJ was completley shot. Ended with a new shaft, now back smooth again.

Still not had it done as the specialist isn't open, however 2 more problems,
have a squeaking noise when driving sounds like a dragging caliper almost a ringing noise, but doesn't go away if you hold the brake so i know its not that, while looking underneath to try and locate what was causing that i noticed the cv boot had gone what are they like to do on these p38's?