You can’t have missed the fevered speculation as to whether Gordon Brown will call an early General Election, just two and a half years into a theoretical five-year term. Though such a gamble sounds absurd, if Mr Brown is considering such a thing it will be for the same reason that the rest of us are wondering: he’s seen the opinion polls.

The so-called ‘Brown Bounce’ appears to have turned round the Tory lead and given Labour the better chance of winning the next election. But how do these sudden opinion poll surges compare with similar situations in the past? And is the past, or are opinion polls, any guide to the future?

You might well be better off with tea leaves and sticking your finger in the air (or through a letterbox), but as you’re reading this for some opinion poll fun, let’s start crunching numbers…

The Liberal Democrats’ ancestry goes back to the 17th Century, but we’ve been going as this party since just 1988. That seems the appropriate point, then, from which to make comparisons – Liberal Democrat poll standing with Liberal Democrat poll standing.

During the lifetime of this party, there have been three new leaders before Mr Brown who’ve immediately turned around their party’s fortunes… And none of them have been ours! So what did the early Britain-wide opinion polls make of John Major (who ended badly), Tony Blair (who ended badly) and David Cameron (who may be starting to end badly)?

John Major

John Major became Leader of the Conservative Party on the 27th November, 1990, and Prime Minister the following day. If politics really does follow patterns, then he sounds like the ideal comparison: the dull, reassuring Chancellor taking over from the proven election-winning superstar who’d started turning the voters off by developing a barking mad messiah complex. Of course, he’d been a top political figure for little more than a year at that point, and in terms of his appeal you could argue he was the mirror image of Tony Blair – both popular because you could more easily imagine them as Leader of their largest competitor party than their own.

However, despite a traumatic and continuing split in the Tory Party over the removal of Mrs Thatcher – perhaps because, unlike the Liberal Democrats, they didn’t have a ‘nice’ image to trash – Mr Major started off with a huge boost. Like Mr Brown, you have to wonder whether this was down to the new leader’s qualities or simply the huge sigh of relief that his predecessor was gone, while Mr Major conversely had a popular war with Iraq to his name.

Whatever the reasons, though, Mr Major had a bounce. In September 1990, the Tories trailed on 36.5%, behind Labour on 46.8%, and the Liberal Democrats – still recovering from our merger blues – were on 9.8%. A month later, Eastbourne saw our first by-election victory, boosting us in the polls to 13.3%, bringing Labour down to 45.9% and sending the Tories into a panic on 33.6%. Mrs Thatcher admitted defeat on the anniversary of President Kennedy’s assassination, 22nd November, and that month’s polls already saw the Tories climbing back to 38.1%.

Once Mr Major was securely in post – well, it looked like it at the time – the December 1990 opinion polls monthly average showed a huge turnaround. Tories on 45.7%, up 7.6% on November; Labour 40.4%, down 4.6%; Lib Dems on 9.1%, down 2.7%. Yes, Mr Kinnock was saying ‘Oh no, we’re doomed’ at a poll rating that would have Mr Cameron crying hallelujah and breaking open the champagne: remember that!