Basically, to cut to the chase, Stop the War has made the putative coming war on Iran a central theme of its forthcoming conference. HOPOI and Communist Students have been disaffiliated from the Coalition (specifically by its Stalinist chair Andrew Murray) as "hostile" to StWC because they are critical of the theocratic regime in Iran, as well as opposed to any "imperialist" attack on Iran (Murray's e-mail is in the press release).
Of course, I don't give a shit about who the Coalition allows in, as I am not a supporter of it. But the issue dramatises the utter lack of democracy within the movement, and the refusal of critical thought too. At the same time, the Stalinist heritage of the CPGB makes me none too supportive of them, despite many admirable features. Follow some of the links below if you want to make your own mind up.