Tracy
In the extreme, if he does not attend an assessment then his claim will be closed.
Would he submit to a Home Assessment? If you think he would then he/you need to speak to his GP, they need to write to ATOS explaining why he cannot attend at their offices, if they still refuse then you can try his MP, but ultimately the decision lies with the Assessment Provider as to whether an assessment is required or not.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
