Ugh, fail.
The Guardian comments sections are a trashbag of political censorship and general idiocy, but I see no evidence that they are being trolled by the Kremlin. A whole lot of people THINK they are, and the Guardian has levelled such accusations (without presenting evidence) but my own experience is that I am routinely accused of working for the Kremlin there, based on no evidence at all. Their view is simply "you disagree with me therefore you must be a paid troll". Making things worse: the Guardian moderators delete vast numbers of comments that would be considered completely acceptable anywhere else, merely for questioning what their articles say.
I think the only way to respond to government-sponsored trolling is to just ignore it. Who cares what someone's motivation is? The only practical response is the same anyway: answer back and be more convincing than they are.