You will need to provide evidence that this is the ‘normal way of working’ and without this support then the pupil falls below age expected/ standardized score. You are going to need strong and secure evidence though over a period of time. If ever unsure it is always worth asking your JCQ link through you examination officer within school – they can come and support through a spot check, as has happened to 6 of the schools I work with. Spot check sounds awful but they are fantastic and really are there to help and avoid problems further down the line! Sorry I can’t be of much more help as without seeing child and evidence it is difficult.
Hope that helps a bit,
The SEND Advisory Team – http://www.sendadvisoryteam.co.uk