The UK Supreme Court’s decision last week that Prime Minister Boris Johnson’s prorogation of Parliament was unlawful is an unprecedented judicial interference in matters concerning prerogative and will undoubtedly be subject to debate for some time. While any analysis of the legitimacy of the prorogation may hinge on the contingencies of the Brexit affair, the Court’s decision may well reverberate beyond the United Kingdom’s borders.

One hazardous implication of the ruling might be its influence on future judicial decisions in other Westminster systems. Canada famously endured its own ‘prorogation crisis’ in 2008. Mere weeks after an election produced a hung parliament and a Conservative minority government, a coalition of the Liberal Party and New Democrats, with the support of the separatist Bloc Québécois, threatened a non-confidence vote after the government’s fiscal update included changes to party financing. In the face of the coalition threat, Prime Minster Stephen Harper sought and was granted a prorogation from Governor General Michaelle Jean. Granted on December 4th, with a resumption date of January 26, 2009, the prorogation straddled the Christmas break and thus affected relatively few sitting days. Nonetheless, because the prorogation delayed a presumptive non-confidence vote, observers immediately debated whether Jean should have refused the request. Some argued she should refuse on the basis the prime minister was clearly violating democratic norms by attempting to avoid a confidence vote, while others argued (correctly, in my view) that she had no choice but to accept the request, because she could not reject the prime minister’s advice on the basis of a vote that had not occurred.

Notably, there was little discussion about whether the courts ought to intervene. This might change in light of the new UK precedent.  However, in the Canadian context in 2008-2009, judicial intervention would likely have constituted its own constitutional crisis. For one thing, the coalition collapsed during the prorogation. In part this stemmed from the government retracting the most offensive proposal in its economic update. But to a significant degree it became clear that the coalition was unstable and deeply unpopular with the public. In short, politics properly sorted out a situation that could have easily resulted in Canadians returned to the polls mere months after a general election or, worse, seen the Supreme Court of Canada decide which political party (or parties) ought to take power. Judicial interference would have been a dramatic violation of the basic separation of powers at stake. In any case, the 2008 prorogation established an important constitutional precedent in its own right. As constitutional scholar Peter Russell publicly revealed, Jean’s decision was in part based on the fact that Parliament would soon reconvene and that the proposed budget would be introduced upon its sitting, meaning an effective confidence vote would not be further delayed. This, in Russell’s view, ensures that future prime ministers cannot prorogue for indeterminate lengths of time, or for any reason whatsoever.

Constitutional conventions, particularly the principle of responsible government, can be tested by unprecedented situations or even unprincipled actions by the relevant actors. But the virtue of convention is flexibility, which ensures that politics remains the means by which political crises are resolved. The UK Supreme Court’s decision may be justified, in that the Brexit situation, the Government’s unprincipled actions, and the unfortunate and obviously detrimental effects of the Fixed-term Parliaments Act 2011, all contributed to a situation that made this specific use of the prorogation power constitutionally unacceptable. I leave that for other scholars to debate. In the Canadian case, however, it is clear that a judicial role would have been thoroughly illegitimate. Across the pond I, for one, hope Canadian judges do not see their UK counterparts as having opened a door they might one day walk through.

Professor Emmett Macfarlane, Department of Political Science, University of Waterloo.