People with learning disabilities are subject to a wide range of potential interferences with their choices and freedoms when they are 'placed' in institutional care services. The cumulative and pervasive impact of these regimes can be monumentally detrimental to self and wellbeing. Some have suggested that a new law, the Mental Capacity Act 2005, may limit the interferences that people with disabilities are subject to in care services. In this thesis, I subject the Mental Capacity Act to a critique drawn from new republican political theory. I argue that far from limiting the interferences that people with disabilities are subject to, the Act creates a mechanism which permits a proliferation of arbitrary interferences in people's everyday lives, with little recourse for people to 'invigilate' such interferences. I base this argument on a critical analysis of case law connected to the Mental Capacity Act, and by critically examining four key mechanisms of enforcement: Independent Mental Capacity Advocates, the Court of Protection, complaints procedures and regulation by the Care Quality Commission. I argue that, paradoxically, a framework for detention introduced by the Act - the deprivation of liberty safeguards - in fact contains more ingredients for ameliorating states of domination in these services than the Mental Capacity Act itself. However, the safeguards also suffer from serious defects. I conclude by discussing what lessons may be drawn from the problems with the Mental Capacity Act and the safeguards for wider reform efforts connected with the UN Convention on the Rights of Persons with Disabilities.