Unite member speaks of "non-communists" and "anti-communists", by which he seems to mean those who did not accept the same definition of communism and marxism that he did.
Throughout my experience in the CPGB in the 1970s, all the people who would be labelled "eurocommunist" certainly thought they were communists - indeed we thought we were considerably better communists than those who schemed against decisions taken at Congresses.
The idea that the Party was somehow taken over by a determined band of anti-communists is just a peculiarly daft conspiracy theory. Since "non-communists" and "anti-communists" would not normally join a communist party, you end up with the idea that they were infiltrated by the intelligence services. History is thus reduced to the manipulations of secret state agencies.
In reality, there were sharp, and legitimate differences of opinion in the CPGB. These became extremely bitter when the group defeated at Congress after Congress refused to accept party discipline. That was the real background to their attack against Marxism Today, and the use of the PPPS against the very body that had created it, the Party.
Unite Member doesn't like Marxism Today - but in reality, when Martin Jacques took over from James Klugmann, and gave the magazine a facelift, it became much more readable, and thus entertaining (yes, entertaining - I am firmly of the belief that political writing should entertain as well as educate people, and should not bore the pants off them). And of course it was controversial - a good magazine ought to be controversial.
Marxism Today didn't lay down a line - it invited discussion and disagreement. Sometimes it printed what many party members regarded as heresy, and sometimes there were articles that were rubbish. That is the risk of any political magazine
And now, decades later, we remember Marxism Today, but I can't even recall the titles of the deathly boring English language publications from the various socialist countries.