The most significant principle of the constitution of the United Kingdom in practice is not the sovereignty of parliament, nor the rule of law, nor the separation of powers. It is that hubris will tend to lead to nemesis. For it is that eventuality that has again and again saved this country from prolonged periods of one-person or one-party rule.
In 1989, Margaret Thatcher was met by cheers of “ten more years,” but she was gone a year later. Tony Blair believed he was politically invincible as he misled the country into invading Iraq. In 2022, allies of Boris Johnson said that he was preparing to stay as prime minister for two full parliaments.
Each successful leader who takes their party into government appears to believe that the height of their political power will last forever. But in every case the body politic eventually regurgitates that prime minister and spits them out. All premierships end in failure.
And this is more a matter of good luck than by design, for there is little formal check or balance to a prime minister absent the folly that usually brings them down. For the constitution of the United Kingdom provides a prime minister in command of a majority with the great might of the “royal prerogative” (supposedly exercised by the monarch on the advice of a PM), combined with the sheer power of a parliament that can make or unmake any law whatsoever. They can even decide when general elections take place.
There are few heads of government in the world with as much practical power at their fingertips as a prime minister elected with a mandate and a substantial majority. There is no need to employ Americanisms like “supermajority”. What a prime minister can do with a normal majority is immense.
But somehow each leader so far gifted with these constitutional super-powers loses power against their will. Each story arc ends in their political demise. Boris Johnson won a thumping majority in 2019 only to be thumbed out of parliament midway through his term by his parliamentary colleagues.
Sometimes these ejections are done by means of a general election. Here the popular vote in and of itself is not that important. The Labour vote in the general election this week, which led to the party's landslide, seems to have not been that different to that which led to the party’s defeat in 2019. It is the distribution and configuration of that vote that matters.
The Conservatives look as if they have received their lowest share of the vote since the days of Sir Robert Peel—that is since the party took on its current name and form in the 1830s. The implosion in their support this week compares to that in 1906 or 1945 or 1997. It is a defeat of historic proportions.
Each time before, however, the Conservative party has managed to come back, though it usually takes more than one election, and sometimes after a period of coalition or “national” government with other parties. That, too, is not inevitable. And unlike previous electoral collapses, in Reform the Tories now have a competing party on the right with a parliamentary foothold. The “natural party of government” thereby not only faces irrelevance but possible oblivion, and even extinction. The party once led by the Duke of Wellington may now have met its own Waterloo.
Yet for all the recurring rises and falls of political power, there is little in our constitutional arrangements which could stop a prime minister and governing party that refuse to be arrogant or complacent, that choose not to spend their time in office sowing the seeds of their own political destruction.
And should we ever have a government that is business-like and competent in the longer-term then they may prove hard to dislodge. It would be a strange experience, after the antics of the last few years. Often in our political history, our political masters turn out to be (or turn out to be seen as) fools or knaves. They are then ejected accordingly, either by their peers or by the voters.
But hubris is not inevitable and so neither is nemesis. If the incoming prime minister and his party do not get carried away with the political and constitutional power they now possess, then they may hold on to that power for a long time. And there is little or nothing in our constitutional arrangements that will stop them.
