Although they can seem awfully important at the time, especially to those who’ve been sweating over their speeches all summer, most party conferences, like the opinion poll bounces they sometimes occasion, fade from the memory very quickly. There are, however, some honourable exceptions – years that have provided high drama and even made a real difference.

In a top-down organisation like the Tory Party, there’s little expectation that its annual gathering can make much difference to policy. After all, it was one of its own leaders, Arthur Balfour, who famously remarked that he’d sooner listen to the opinions of his valet than those of the Conservative Party Conference. Yet there has been the odd exception that proves the rule.

Perhaps the most famous was in 1950, when calls from the floor led the leadership to promise to build 300,000 houses a year, a commitment Churchill thought unwise until Macmillan managed to deliver on it in the early 1950s, thereby cementing a growing reputation that eventually helped him win the top spot. And, although they’ve been few and far between, votes taken at party conference may once or twice have pushed the leadership into taking a tougher line than it might otherwise have adopted, the one held after a heated debate on immigration in 1969 being an obvious case in point. That said, various home and shadow home secretaries have been subjected sometimes to vituperative criticism from the floor over their refusal to restore hanging and flogging, but all of them resisted those siren calls.

In the end, and perhaps fittingly, the biggest impact of conference for the Tories has been on leadership rather than policy. There have been two years – 1963 and 2005 – which turned into beauty contests between rival candidates and where reputations were won (Alec Home and David Cameron) and lost (Rab Butler, Lord Hailsham and David Davis). Meanwhile, it was Iain Duncan Smith’s woeful performance at the 2003 conference – “the quiet man is here to stay and he’s turning up the volume!” – which, notwithstanding 17 stage-managed standing ovations, finally helped to trigger his removal.

Turns out, then, that all that time spent slaving away over your speech during the summer may not be wasted after all. “You turn if you want to” told voters that Margaret Thatcher was going to stay the course. “Let me take you on a journey to a foreign land” made it clear that William Hague had finally abandoned all thoughts of a fresh start. And in 2007, Cameron’s “So, Mr Brown, what’s it going to be? You go ahead and call that election…We will fight, Britain will win” went a long way – along, of course, with George Osborne’s announcement on inheritance tax at the same conference – to persuade Brown to bottle it, thereby blowing Labour’s best and only chance to win after Blair’s departure. The rest, as they say, is history…