The decision to hold a referendum on EU membership might be the dumbest political error by a UK prime minister in the past century.

Before too many heads explode, let us (in a manner politicians would appreciate) tease the definitions and conditions to favour our own over-reaching argument. Tony Blair’s decision to support the Iraq War will surely be seen to have caused more suffering. Anthony Eden’s barmy scheme to regain Suez will have done greater damage to the UK’s reputation. Neville Chamberlain and his fellow appeasers will retain the blackest name in history books.

All these decisions were, however, responses to unavoidable international crises. None was a political scheme to further party interests. That’s what we’re discussing here.

Nobody forced Capt Cameron to chart a course towards Referendum Bay. The crisis in the euro zone made the waters choppier, but it was the threat of mutiny from his own crew and the sight of Ukip pirates on the port side that caused the sickening swerve.

Offering London the most comical maritime kerfuffle since the Sex Pistols blasted the House of Commons, Nigel Farage (HMS Leave) and Bob Geldof (the good ship Remain) spent Wednesday afternoon bellowing at one another from adjacent bits of the Thames. English soccer fans screech about “voting no” while weeing in foreign fountains. The polls refuse to shift towards “remain”.

Political screw-ups

Labour remained out of office for the succeeding 13 years. But before the UK’s recent shift to fixed-term parliaments the calling of elections had always been a lottery. All mistakes are forgivable.

A better contender still would be Thatcher’s decision to implement the poll tax in 1989. To this point, despite her passion for division, the Iron Lady and her advisers had shown an eerie gift for connecting with unfashionable yet populous corners of Middle England. The sight of anarchists kicking police horses in Trafalgar Square would not have much cheered her. But, politically, the plunging poll ratings in blue-rinse shires were more serious still. Thatcher’s defenestration followed swiftly.

The poll tax was, however, mainly a disaster of presentation. Four years later John Major’s government introduced the only modestly tweaked council tax to no great furore. Little lasting damage was caused to the nation.

David Cameron’s referendum strategy is dumber in every regard. It seemed, at first, like a magnificent wheeze. On the one hand he offered a sop to rebellious Eurosceptic MPs within his own party. More cunningly still, he had devised a knobbly stick with which to wallop Farage and the paranoid Ukip insurgency. Even the most deranged Faragist candidate couldn’t claim that Ukip would secure an overall majority in the 2015 election. (It ended up with just one seat.) The only major party offering a referendum was the Tories. Any split in the right that led to significant Ukip gains might deprive the Conservatives of power and so hobble any chances of a vote on EU membership. Therefore Eurosceptics needed to vote Tory. Got it?

Some cynics have argued that the plan worked a little too well. The theory goes that, like most analysts, Cameron didn’t think an overall majority was within reach. If forced into another coalition with the Liberal Democrats he could (after producing an onion) tearfully claim that nasty Nick Clegg wouldn’t let him have his referendum.

There is every possibility that the scheme is about to fail catastrophically. The UK will vote to leave the European Union. Cameron will be forced to resign, and the faux-befuddled Road Runner to his off-beam Wile E Coyote will take over the reins. Boris Johnson (for it is he) will then watch helplessly as Scotland – sure to vote “remain” – finally manoeuvres itself out of the United Kingdom.

Then again. As happens in referendums, the electorate may drift back to the status quo, and Cameron may get to keep his country. With one bound he will be free. But it will still be among the dumbest risks any prime minister has taken.