Barring Pitt in 1784 quoted below, when else did UK Parliament's legal sovereignty trample and overpowere the electorate's political sovereignty?
The true answer to the objection thus raised appears to be that the observance of the main and the most essential of all constitutional rules, the rule, that is to say, requiring the annual meeting of Parliament, is ensured, without any necessity for Parliamentary action, by the temporary character of the Mutiny Act, and that the power of Parliament to compel obedience to its wishes by refusing to pass the Act is so complete that the mere existence of the power has made its use unnecessary. In matter of fact, no Ministry has since the Revolution of 1689 ever defied the House of Commons, unless the Cabinet could confide in the support of the country, or, in other words, could count on the election of a House which would support the policy of the government. To this we must add, that in the rare instances in which a Minister has defied the House, the refusal to pass the Mutiny Act has been threatened or contemplated. Pitt's victory over the Coalition is constantly cited as a proof that Parliament cannot refuse to grant supplies or to pass an Act necessary for the discipline of the army. Yet any one who studies with care the great “Case of the Coalition” will see that it does not support the dogma for which it is quoted. Fox and his friends did threaten and did intend to press to the very utmost all the legal powers of the House of Commons. They failed to carry out their intention solely because they at last perceived that the majority of the House did not represent the will of the country. What the “leading case” shows is, that the Cabinet, when supported by the Crown, and therefore possessing the power of dissolution, can defy the will of a House of Commons if the House is not supported by the electors. Here we come round to the fundamental dogma of modem constitutionalism; the legal sovereignty of Parliament is subordinate to the political sovereignty of the nation. This the conclusion in reality established by the events of 1784. Pitt overrode the customs, because he adhered to the principles, of the constitution. He broke through the received constitutional understandings without damage to his power or reputation; he might in all probability have in case of necessity broken the law itself with impunity. For had the Coalition pressed their legal rights to an extreme length, the new Parliament of 1784 would in all likelihood have passed an Act of Indemnity for
illegalities necessitated, or excused, by the attempt of an unpopular faction to drive from power a Minister supported by the Crown, by the Peers, and by the nation. However this may be, the celebrated conflict between Pitt and Fox lends no countenance to the idea that a House of Commons supported by the country would not enforce the morality of the constitution by placing before any Minister who defied its precepts the alternative of resignation or revolution.
These quotes below can serve as context. p. 260.
How, it may be said, is the “point” to be fixed at which, in case of a conflict between the two Houses, the Lords must give way, or the Crown ought to use its prerogative in the creation of new Peers? The question is worth raising, because the answer throws great light upon the nature and aim of the articles which make up our conventional code. This reply is, that the point at which the Lords must yield or the Crown intervene is properly determined by anything which conclusively shows that the House of Commons represents on the matter in dispute the deliberate decision of the nation. The truth of this reply will hardly be questioned, but to admit that the deliberate decision of the electorate is decisive, is in fact to concede that the understandings as to the action of the House of Lords and of the Crown are, what we have found them to be, rules meant to ensure the ultimate supremacy of the true political sovereign, or, in other words, of the electoral body.1
By far the most striking example of the real sense attaching to a whole mass of constitutional conven-tions is found in a particular instance, which appears at first sight to present a marked exception to the general principles of constitutional morality. A Ministry placed in a minority by a vote of the Commons have, in accordance with received doctrines, a right to demand a dissolution of Parliament.
1 Cf. Bagehot, English Constitution (1872 ed.), pp. 25-27.
The personal influence of the Crown exists, not because acts of State are done formally in the Crown's name, but because neither the legal sovereign power, namely Parliament, nor the political sovereign, namely the nation, wishes that the reigning monarch should be without personal weight in the government of the country.