Happy Christmas (War Is Over). John Lennon probably didn’t have the decades long Conservative dispute over Europe in mind when he wrote that, but the message seems very apt this year after almost the entire Tory parliamentary party trooped through the lobbies in support of its leader’s plan to take Britain out of the EU.

It was back in 1971 that Lennon released his blockbuster Christmas single. At the time, the Conservatives were largely united behind the idea of joining the European Economic Community. So few could have anticipated that an internecine political war lasting almost half a century was taking hold. In the key Commons division of that year, only 39 Tory MPs voted against joining the EEC; they were more than counterbalanced by 69 Labour MPs who sided with Edward Heath’s administration.

But take hold the Tory war certainly did. Many people remember the poll tax as the pretext for the bringing down of Margaret Thatcher. In fact, the issue of European integration was the more profound cause, with Tory Europhiles reacting in horror at her famous “no, no, no” denunciation of the idea of transferring more national sovereignty to Brussels and organising to oust her.

By the time of the Maastricht Treaty in the early 1990s, concerns about the loss of sovereignty inherent in the European project’s pursuit of political and economic union had set in with scores of Tory MPs and millions of Tory voters.

This was the era of the “whipless wonders” – stripped of the party whip by John Major over their Maastricht rebellions – and of his Cabinet “bastards” who were doing all in their power to stop him signing us up to the looming single currency.

The European issue certainly led to Major being perceived as a weak and hapless character, of whom Tony Blair remarked stingingly at one PMQs: “I lead my party, he follows his.”

During these years, the dominant media narrative was as follows; Europe was obviously the future and those Tories who disputed this represented a tiny rump of right-wing “little Englanders” who were to be mocked as unable to come to terms with the modern world. Much commentary was based around the idea of Eurosceptics being mentally ill. This seemed to be the essence of Major’s observation that whenever he heard the name of sceptic MP Sir Richard Body he also heard the sound of “white coats flapping”.

This narrative took an even stronger grip after Jacques Delors turned the Labour party in a pro-Brussels direction. He did so by selling the idea that the European Project could be used to advance progressive policies that had flopped at the ballot box when tested against the Tories in general elections.

Out of office, the Tory leadership fell into the hands of a series of Eurosceptics: William Hague, Iain Duncan Smith and Michael Howard. But their failure to recover sufficiently from the 1997 landslide that Blair inflicted on Major led some of the commentariat to conclude that Euroscepticism was a blind alley for the party.

Over the last decade the issue of Europe has, of course, consumed two further Conservative PMs, David Cameron and Theresa May. This turmoil cemented for some the view that the Tories would never rule in a stable manner again, until they expunged the anti-Brussels brigades from their party.

And look what has happened. The very opposite. The expunged ones are those who refused to accept the verdict of the British electorate that European integration is not for us. Most are gone from the Commons, many from the party itself. And their departure did not lead to a collapse in Tory electoral fortunes as voters fretted about the party “lurching to the Right”. It led to a landslide victory for Boris Johnson and Brexit. The tiny rump of Tory pro-EU types left in the Commons – the likes of Greg Clark, Stephen Hammond, Vicky Ford and Steve Brine – all signed up to a pledge to back Johnson’s withdrawal deal.

There is no longer a Tory civil war over Europe. It has been brought to an end by means of a decisive victory for one of the competing sides. And it wasn’t the sensible technocrats and self-styled “liberal Tories” who came out on top.

No, it was the ones smeared as mentally-ill and bigoted. The ones whose counterparts in Ukip were disparaged by a Tory leader as “fruitcakes, loonies and closet racists, mostly”.

Doubtless new fault lines will emerge over time within the Conservative parliamentary party. Any entity comprising of a professional politician for every day of the year is bound to involve different factions and people with different lists of priorities.

There may still be a last flurry of Tory tensions on Europe if we approach the end of next year without a trade deal in place and some begin agitating for an extension to the transitional period. But the brute size of Boris Johnson’s majority means he can swat such an episode away however he chooses.

This month's election saw the testing to destruction of the idea that resisting European integration amounted to obsolete right-wing folly. Intervention after intervention in the election debate from the likes of Major, Heseltine, (Chris) Patten and many more – all given widespread coverage – failed to stick.

Tory EU-philes fought a dirty, personal campaign because they always feared they couldn’t win over the British people on the substance. So John Redwood’s intently staring eyes or Tony Marlow’s stripy blazers or Boris Johnson’s colourful love life were all, at various times, scorned and contrasted with the sane, moderate demeanour of the EU believers.

That story doesn’t work any more either.

In a little over a month a Conservative Government with a landslide majority will execute its primary task: taking the United Kingdom out of the European Union. And it will be done without a single Tory voice in the Commons opposing it. Happy Christmas. This war really is over.