I have bitter experience of this type of thing (ie. seeing schools do things which I know will leave my Ds totally unsupported).
I would want to have a meeting with those who made the decision and ask them to outline the benefits of this system to you.
Try not to argue against it at this meeting, simply ask them what benefits they see and what evidence they have for thinking this. (try to keep calm-which is not easy!). Make lots of notes and concentrate on their arguments, rather than arguing the points at this stage.
Then you can go home and think about your response in your own time. I always find it really hard to respond to them in the meeting itself, as I'm too emotionally charged, so I let them do the talking, then go home and process my own thinking on it.
Once you've weighed up the arguments (theirs and yours, for and against), you set it all out on paper and send copies to everyone-LEA (if there's anyone left there!), governor in charge of SEN, HT, DH, SENCO, Year Head, everyone, and ask that your arguments/suggestions be considred in another meeting on...(you sugest 2 dates for them to choose from-why should they always tell you when to come in for meetings?).
This way, you are wrestling control from them and putting yourself in a position of power.
You then set the 'tone' of the meeting and put all your points across, explaining point by point why you think this won't work and what you would like to see instead.
(At least, that's what I'd do if I had the discipline, and what my parenting course last week suggested. In reality, I just go in and shout alot then burst into tears!
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