Roger Lloyd Pack

I first spotted him as, er, the rather "Earthy" character of Owen Newitt in Vicar of Dibley, with Dawn French- a favorite of my whole family. http://www.bbc.co.uk/drama/faces/roger_lloydpack.shtml

Here is another guest on both Who and Potter.

Barty Crouch, Sr- and well played- in Harry Potter.
http://www.veritaserum.com/movies/actors/rogerlloyd-pack.shtml

John Lumic- a dying man who becomes the new Cybercontroller on the alternate dimension that takes Mickey, Rose, and Jackie in Dr Who.
http://www.bbc.co.uk/norfolk/content/articles/2006/05/13/tv_doctor_who_roger_lloyd_pack_may06_feature.shtml