The extraordinary events of the past 48 hours in London have shown the vulnerability of constitutional systems that rely heavily on the expectation that key figures will abide by conventional rules of good behaviour.
All constitutions have some unwritten rules that guide the behaviour of key actors, but the British constitution is particularly reliant on these conventions due to the fact that the UK’s constitution is not set out in a single document. Britain’s system of government is instead found is an uncodified series of laws and practices that have evolved gradually over time.
Indeed, often, the established practice means that the reality is the opposite of the official legal situation. For example, on paper, the queen is free to choose whomever she wants to act as prime minister, but this power is qualified by the constitutional convention the she will always choose the person who has majority support in the House of Commons.
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Under normal circumstances these “let’s pretend” arrangements can be relatively benign way of keeping continuity between the present and the past. Indeed, in the past, the gradual development of conventions constraining the monarch’s power allowed the UK system to evolve gradually from a system of royal rule to a constitutional monarchy while keeping the same institutional framework.
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However, this system is vulnerable when faced with actors who refuse to play by the conventions of good behaviour on which they depend. Like Donald Trump, Boris Johnson consistently showed scant regard for institutions or norms of constitutional decency.
In 2019, one of his first acts was to seek to abuse the power of the prime minister to begin and finish parliamentary sessions by using it to close Parliament for a lengthy period in case MPs sought to thwart his Brexit plans.
His reaction to the evaporation of his parliamentary support was similar. While his predecessors acknowledged that a lack of parliamentary support meant they had to go, Johnson argued that he had a direct mandate from the British people and that he could therefore carry on.
This is where the UK’s reliance on constitutional conventions threatened to cause a constitutional crisis. Because in theory the queen, not parliament, nominates the prime minister, it was only a matter of convention that a leader who loses the support of his party would resign.
Replacement
If Johnson had continued to cling on, he could ultimately have been removed through a motion of no confidence in parliament, following which the queen could have fired him, but this would have raised the awkward question of who would be nominated to replace him.
Indeed, the issue of a replacement has not entirely been resolved. In the past, Conservative MPs would have rapidly elected a new leader who would then take over. However, since 2001, Conservative Party members have the final say in electing a leader in a process that takes months.
Until now, there has been no problem with the sitting prime minister staying on in a caretaker fashion and abiding by the convention that a caretaker government should avoid making significant policy decisions. But given Johnson’s track record of violating constitutional conventions and his claim that he holds a personal mandate from the British electorate, many will not trust him to respect the limits of a caretaker prime ministership.
The past few days have underlined that the UK is, ultimately, a parliamentary system. Despite his claims to a personal mandate, Johnson could not survive without the support of his MPs. This is in marked contrast to the United States, where the presidential nature of the system meant that Donald Trump had been directly chosen by Republican voters in primaries and was therefore less dependent on support from Republican members of Congress, few of whom were brave enough to break with him when he refused to accept that the game was up for his presidency.
That said, British politics now faces months of uncertainty. The election of party leaders through a vote of party members sounds more democratic that allowing MPs to make the final decision. But it sits awkwardly with the parliamentary nature of the British system. The Conservative Party membership is small, highly unrepresentative and holds views considerably more extreme than those of most voters.
There is a considerable risk that an extremist minority of Tory MPs may succeed in placing one of their number on the ballot and that the membership will opt for a candidate who has minority support among MPs. There is also the risk that Johnson will seek to use his period as caretaker prime minister to manoeuvre against enemies or even to try to engineer an improbable comeback.
That said, it does seem that the Johnson era is coming to an end, albeit a drawn-out one. But the damage his hyper-partisan, no-holds-barred approach has done to a constitutional system that has relied heavily on the expectation that key players abide by unwritten rules of good behaviour will be lasting.
Though reliance on unwritten norms is particularly strong in the UK constitution, all constitutions rely, to a degree, on good faith and adherence to unwritten norms on the part of key actors. Many key features of the Irish constitutional order such as the independence of the judiciary or editorial independence at RTÉ, rely as much on political culture as legal rules.
With politics in many European countries, including Ireland, increasingly partisan and rancorous, the Johnson era may cause reflection beyond the UK on how constitutional balance can be maintained in a no-holds-barred political era.
Ronan McCrea is Professor of Constitutional and European Law at University College London.