LAs erroneously took children into care, exercising powers under statute. Both the children and their parents sued for negligence. HL denied the claim, saying that for the act of a public authority to be liable in tort it had to be justiciable. This would only be the case if (1) the impugned decision did not involve a weighing up of public interests, which it was the role of parliament and public bodies to do ,(2) the decision was ultra vires, and (3) the impugned action was ‘operational’ (i.e. didn’t involve the exercise of discretion) rather than being one of ‘policy’ (i.e. involving discretion)
