In R (VC) v SSHD [2016] EWHC 273 (Admin) a brave (the harsh would say misguided) attempt was made to rely upon the MCA in the context of a challenge to immigration detention to an individual with mental health difficulties. The claimant argued that: (1) pursuant to the public law duty of enquiry and in order to facilitate compliance with the MCA 2005, the SSHD was under an obligation to arrange for a detainee to have a capacity assessment where there is a reasonable suspicion that the detainee may lack capacity; (ii) where a detainee is assessed as lacking capacity in relation to areas of decision making that are the sole responsibility of the SSDH the SSDH is obliged to make those decisions compliantly with section 4 MCA 2005, namely in the detainee's best interests; and (iii) in order to make best interests decisions the SSHD must ensure that the incapacitated detainee's wishes and feelings are put forward, and that the detainee is supported to participate so far as is possible and that the detainee's interests are represented.

Unsurprisingly, perhaps, these arguments ran up against the immovable barrier of construction (clearly identified in Re MN) that the MCA is solely concerned with decisions done for or on behalf of a person. As HHJ Seys Llewellyn QC noted “if the Act thereby required any decision "affecting" a person without capacity to be made in his best interests it would lead to remarkable results: for instance, on his conviction in an ordinary criminal case his individual best interests would trump other interests when considering whether or for how long he should be imprisoned.” He therefore agreed with the submission of the SSHD that “the MCA 2005 is concerned with decisions which would usually be made by an individual as part of their personal autonomy and so reflect their wishes and feelings and does not purport to extend to any other type of decision such as those made under immigration powers tax powers or criminal justice powers and it cannot do so.”