judders;Clutch friction plates linings contaminated with oil or grease,
        Faulty or distorted pressure plate or diaphragm spring.
        Worn or loose engine or gearbox mountings.
       clutch friction plate hub or gearbox input shaft splines worn.
and thats what it says in the Haynes,
from chris Addlestone  Surrey

I would certainly give it a little time to bed in first. If the problem
persists after a few hundred miles, take it back and complain. Remember that
according to the "supply of goods and services regulations 2002" any fault
which comes to light within the first six months is deemed to have been
there at the time of supply unless the supplier can prove that it was not.
Brian.

Something wrong. Never heard of a clutch needing to be bedded in (brakes
yes).
First check would be engine and gearbox mountings.
If they're ok, it's inside the housing. As said- contaminated friction
surface,  release bearing and/or diaphragm spring faulty.
DaveK.