The House of Lords had to decide whether it was appropriate to grant an injunction to restrain secondary picketing on the ground that it was not covered by statutory immunities concerning trade union action as part of a trade dispute.

The British Constitution is firmly based on the separation of powers in that Parliament makes the laws and the judiciary interpret them.

This was a negligence claim involving considerations of Art 6 European Convention on Human Rights and Fundamental Freedoms.

The executive must never be put in a position where it effectively decides a case in the sense that it could order a court to dismiss a case. What matters is whether the effect of a legal provision is to give the executive a right to make decisions about people’s rights which should be made by the judicial branch of government.

The Court of Appeal had to decide whether the courts must review the substance of an executive decision in human rights cases.

The role of the executive is to make decisions where it has access to special information or expertise or where the nature and consequences of the decision require accountability to the legislature and to the electorate. The role of the judiciary is to make sure that the executive complies with all formal requirements, considers matters rationally, and makes decisions, especially where human rights issues are involved, in accordance with the principle of proportionality.

Parliament, the executive, and the courts each have their distinct and largely exclusive domain. Parliament has a largely unchallengeable right to make whatever laws it thinks right. The executive carries on the administration of the country. The courts interpret the laws and see that they are obeyed.