First of all, getting a motion put up can be a nigh-impossible task in itself if no-one's prepared to second it (and in workplaces permeated by fear of management reprisals, that's a very real danger) and - if the motion is critical of current union practises - the branch officials themselves may be reluctant to push the motion even if passed at branch AGM level. If passed at Branch AGM lelvel, there's always the chance of soem standing-orders commitee getting it struck off. If it somehow gets past all those hurdles, there's the likelyhood of it not getting past the national AGM. If (and you see the diminishing chances here, don't you?) it gets past the national AGM, there's every chance it will still just be ignored. Maybe next year you come back with a censure motion - which similarly can be ignored.