QUITE a few politicians have seen their careers prematurely ended over Britain’s relationship with Europe. But none quite as spectacularly as David Cameron.

The prime minister looks like the man at the roulette table who bet everything he owned on red – only for the ball to land on black.

Mr Cameron has enjoyed a fairly good run of luck in politics up until now.

He became prime minister after his party won only 36 per cent of the popular vote in 2010. He won a majority at last year’s general election with just 37 per cent. And in between, he took a big risk by holding a referendum on Scottish independence – and won.

But Mr Cameron couldn’t bear to walk away from the table while he was ahead. He hoped he could finally settle the divisions over Europe which have riven his party for decades, by asking the public to endorse the deal he negotiated with the European Union.

Then his luck ran out.

In calling the referendum, Mr Cameron was following the example of Harold Wilson in 1975, when it was Labour that was deeply split over Europe. Wilson decided that a plebiscite, with ministers free to campaign as they wished, could be the solution to his difficulties.

But if Mr Cameron hoped Wilson’s solution might work for him, he may have overlooked a few facts about 1975.

Wilson had the press, the business world and the opposition – under new Conservative leader Margaret Thatcher – overwhelmingly on his side. And in those days, three quarters of the population voted for the two main political parties, with no equivalent of Ukip or much support for nationalist parties.

What’s more, even though cabinet ministers were set against each other, the temperature of the political argument was pretty cool compared with today. There was not the intemperate argument about immigration or the cynicism about expert opinion.

Wilson won his referendum convincingly, by 67 per cent to 33. But if there had been any kind of healing effect on his party, it did not last.

His resignation the following year may not have been directly related to the referendum – he insisted he had always intended to resign when he was 60 – but it heralded renewed infighting.

The anti-European left of the party was in the ascendant. Within six years of that referendum triumph, Labour split with the departure of the heavyweights known as the Gang of Four, in large measure because they were angry at the hostility to Europe.

Eight years after that referendum, the party went into a general election with arch Euro-sceptic Michael Foot as leader, committed to leaving the European Community, and came pretty close to political annihilation. The road back to government would be long and difficult.

A lot of political careers might have turned out differently if not for the European question. Roy Jenkins might have been Labour prime minister, as he was widely tipped to be at the end of the 1960s. The same is arguable about Denis Healey. Margaret Thatcher’s premiership might not have unravelled the way it did. Neither would that of John Major, who ended up trying to lead his party into the 1997 general election with 200 candidates opposing his European policy. And Euro-friendly heavy-hitters such as Michael Heseltine and Kenneth Clarke might have had their shot at leading the party.

With less than 48 hours of hindsight, it’s already bewildering that Mr Cameron could have put his career on the line in the way he did. But his premature political demise, only a year after winning the first Conservative majority in parliament since 1992, is not the most important issue.

Wherever you stand on the European Union, the referendum result has thrown all the pieces of our politics, our economy and even our United Kingdom into the air. No one can predict how they will look when they finally land.