Calamity has befallen Labour and the Liberal Democrats. But there is another once elemental force in British politics whose sap has been drained almost to the last drop.

Two generations of progressive Conservatives have spent the last four months actively plotting to undermine the man who has just led the Party to its largest majority in 32 years. Their motivation was partly personal but fundamentally ideological.

The decision of these liberal Tories to throw everything into subverting Boris Johnson’s Brexit strategy reached its denouement with 21 of them being stripped of the party whip. Such was their punishment for ceding their own government’s control of the legislative process to the Opposition. Seventeen of these rebels are no longer in the House of Commons.

Former Chancellors of the Exchequer, Ken Clarke and Philip Hammond together with ex-Cabinet ministers, Dominic Grieve, Sir Oliver Letwin, Justine Greening and David Gauke, have gone into political oblivion. They followed where the “three amigoes” of “the independent group” Anna Soubry, Heidi Allen and Sarah Wollaston led. Anyone looking for evidence of the London-centric commentariat’s confusion of analysis with wishful-thinking need look no further than the expert opinion that only eight months’ ago maintained that ‘Change UK’ might represent the future of British politics.

So much for yesterday’s poker players. What of the previous generation of liberal Conservative ‘big beasts’? Six days before the polls opened, Michael Heseltine and Sir John Major allied themselves to Tony Blair in a joint appeal to the electorate to vote only for candidates that promised a second Brexit referendum. Since every Conservative candidate opposed the second referendum, the former Prime Minister and his Deputy were calling for the defeat of their own party.

the Party turned in desperation to Johnson – the political equivalent of OFSTED placing a school in ‘special measures’.

How the mighty have fallen. Major, Heseltine, Ken Clarke, Rory Stewart, Sam Gyimah – five men who have all stood for the leadership of the Conservative Party and who are now entirely estranged from it. What would become of the once stout party without them? Guto Bebb, one of the 21 dissidents, explained that because of Johnson, the Tories “are no longer a broad church but rather increasingly an obsessed sect.”

In reality, it was Theresa May’s broad church that seven months’ ago was reduced to 8.8 per cent of the vote and came fifth (behind the Greens) in the European Parliamentary elections, a historic low that led to the Party turning in desperation to Johnson – the political equivalent of OFSTED placing a school in ‘special measures’. His ‘sect’ has just recorded an extraordinary fourth-term election triumph which no previous Tory leader has achieved since the 1832 Reform Act.

Future generations of historians and political science postgraduate students will seek to find method in the miscalculation that has seen these two generations of liberal Tories commit such mass seppuku. This is the passing of the Whig grandees, but with added electoral humiliation.

In analysing it, the frame of reference will be the two liberal Tory generations’ fatal fusion of conservative progressive economic and social views with belief in the regulatory efficacy of the European Union. They concluded not only that the two were complementary but inseparable.

It is thus little wonder that they are scornful of Boris Johnson’s repeated assertions during the election campaign (and in the hours of victory) that he is leading a “One Nation Conservative” Party. How could he be, when they were the One Nation in Conservatism?

Yet, besides his commitment to get Brexit done, what is especially right wing about Johnson, either in his record as Mayor of London or in the programme he has laid out for government?

His manifesto’s commitments are dismissed for their timidity. Another way of looking at them is to identify the absence of market-led solutions to current problems. The Thatcherites thought the unthinkable. Such disruptive instincts are alien to Johnson. As a steady-as-you-go Conservative, he has much in common with David Cameron’s easy temperament and acceptance of the world as he finds it.

If the rebels could have overcome their intrinsic Brussels-Jacobitism, they could have rejoiced that there was little in Johnson’s manifesto that equated to taking the Tory Party down a path of free-marketeer ideological purity. Which part of the increases to the health budget or the stalling of reform in the education sector did the Majors, Heseltines, Gaukes and Grieves find so noxious?  Johnson’s manifesto would have been perfectly acceptable to Rab Butler or Iain Macleod.

Is there much evidence that the new intake of Conservative MPs – many representing previously “unwinnable” economically deprived areas –  are enemies of liberal, moderate, Toryism?

By making Brexit-loathing the definition of “One Nation Conservatism” the old guard has not only written a reductive diagnosis of its own condition but imagined internecine opponents where no such hostility needed to exist.

Is there much evidence that the new intake of Conservative MPs – many representing previously “unwinnable” economically deprived areas –  are enemies of liberal, moderate, Toryism? New MPs like Theo Clarke (Stafford), Virginia Crosbie (Ynys Mon), Jonathan Gullis (Stoke-on-Trent North) or Laura Trott (Cameron’s special advisor, now MP for Sevenoaks) are not noted for their commitment to the Chicago School or for eulogising the life and times of Augusto Pinochet. If the now departed “One Nation Conservative” old guard believe that their party has been on a long dissent into madness ever since Ted Heath lost the leadership then they have developed amnesia about what many a Tory MP in the 1970s thought, said and sounded like.

Pique at being ignored over Brexit has led the Major and Grieve generations of “One Nation Conservatives” to walk out on their party because they have aligned their creed with opposition to Brexit. Their tantrum deprives the Conservative Party of their talents. But it ultimately changes little. With Brexit done, Johnson has the temperament and the personnel to lead a decidedly One Nation Conservatism without them.