A man who was told he had a “fundamental right to sex” despite not understanding the issue of consent, has been refused permission to pursue sexual relationships by the supreme court. The 36-year-old man, referred to as JB, is autistic and has impaired cognition. He has been assessed as presenting a “moderate risk” of sexual offending to women, particularly to those who are vulnerable, because he is unable to understand that consent is relevant in sexual situations and that attempting sex without consent is likely to be a criminal offence. JB, who cannot be identified, has been since 2014 subject to a care plan by his local authority, which has imposed significant limitations on his freedoms. But in 2019, the court of protection, which considers issues relating to people who may lack the mental capacity to make decisions, ruled JB had the right to pursue sexual relations because he was “entitled to make the same mistakes which all human beings can, and do, make in the course of a lifetime”. Mrs Justice Roberts, the first judge to hear the case, added that insisting that JB understood the issue of consent before being allowed to pursue sex would be discrimination because it would “impose on him a burden which a capacitous individual may not share”. After the court of protection found in JB’s favour, the local authority appealed to the court of appeal, which found for the local authority. JB then took his case to the supreme court, the UK’s final court of appeal. On Wednesday, five judges agreed with the court of appeal ruling, unanimously dismissing JB’s appeal on all grounds. In a ruling that will have far-reaching consequences, Lord Justice Stephens said the case raised issues of profound significance. He said the Mental Capacity Act 2005 and the court of protection “do not exist in a vacuum but are part of a wider system of law and justice, and so must take into account the need to protect others”. “The court for protection should have regard to reasonably foreseeable adverse consequences, with the aim of protecting members of the public as well as persons who may lack capacity,” he said. It is the first time the courts have been asked to decide whether and on what basis the law should act when someone without capacity asks for permission to act in a way that may harm others. In his legal blog, Alex Ruck Keene of 39 Essex Chambers said the ruling was significant because it gave rise to the wider question of what sexual consent should mean. The ruling could, he said, lead to a re-examination of many past cases.