"Umm, no, it's perfectly OK to voice your opinion (for instance, what your conclusion would be of a case, based on what you know of it), but you cannot state such an opinion as fact, because that is libel."
Going by some posters above, who are saying that saying 'allegedly' (or, presumably, 'in my opinion') won't suffice to deflect libel claims, and that merely saying that *someone else* said something is libel if what someone else said was libelous, that isn't the case.
You could make an argument that just requiring people to say 'allegedly' won't help, because then everyone will just say it all the time and nobody will consider it a real qualifier. So, that would suggest that saying 'in my opinion' (which would essentially be the same) or 'allegedly' really aren't a valid defense, as was pointed out above - and that, in that case, you are in fact *not* free to state your opinion, as it can never be known whether you 'really meant it'.
Or whether other people were likely to think that you meant them to think that you meant it even though you said you didn't mean it...
It quickly devolves into utter impossibility. To my mind, you either quash all discussion of anything controversial, force people to make arbitrary judgments on their own and hope that nobody notices if they get it wrong, or allow people to say things *unless their intent was specifically to harm the individual, and with knowledge that the information was false*.
Of course, my understanding is that in the UK you can libel people even if you're telling the truth, so maybe trying to make any sense out of it is a lost cause to begin with...