in television, and not much else. See
http://en.wikipedia.org/wiki/ITV_plc and
http://en.wikipedia.org/wiki/ITN . The full picture is slightly complicated - there are some other companies involved - but there's no big mogul or megacorporation controlling it all from outside.
They do a few more 'bleed and lead' or 'human interest' stories than the BBC (or Channel 4, for whom ITN also produce the news programmes), but nowhere near as much as ABC, CBS, NBC, FOX, etc.
I'd say that interviewing people who don't like Kerry isn't 'smearing' him. 'Smearing' means digging up questionable dirt on someone, blaming him for things he didn't do or say, and so on. Did they show any Democrats? Since the convention is on, I'd expect they did.