Next year’s election has been touted as the most significant for a generation. But then they always are.

But after a five-year wait for this general election, we may be asked to go to the polls again even sooner than we think. For while there is legislation saying the next government will last five years, like the current administration, the realities of politics – and a quick bit of opportunism – may see an election called within two years of the 2015 vote. Consider this scenario: Ed Miliband wakes up on 8 May next year and discovers he is prime minister. Not an unlikely event considering the polls. Labour has been sitting ahead of the Tories since early 2012, granted with the odd blip here and there. But the party has been in the lead for the past two and a half years. Current predictions, thanks to the electoral system and constituency boundaries, give Labour a majority of just more than 30.

But with the economy expected to pick up, and the Kinnock Factor of Miliband, it would be surprising if the Tories did not cut into the lead in the polls in the run-up to election day. There is precedence here: In 1964, Harold Wilson went into the election with polls giving him a majority of anywhere from 12 to 28. He formed a government with a majority of just five. Likewise in 1992, the country went to the polls with Neil Kinnock’s Labour party on course to get a slim majority, but instead John Major won more votes than any other prime minister in British history. The Tories know how to cast doubts on untested Labour leaders.

So Miliband wakes up the day after the election with a smaller than expected majority, but still large enough so that he can form a government. But what can he do? Splashing the cash is out – a Labour victory does not mean the country is suddenly back in the black and the last thing Ed Balls will want to be accused of is being reckless with a growing economy. It will be the symbolic measures that will dominate Miliband’s first year in office – axing the bedroom tax, halting NHS reorganisations, tinkering with the more unpopular aspects of Michael Gove’s school reforms. But once those headline-grabbing moves are out of the way, Miliband will find himself beholden to the rabble-rousers in the Labour party to keep the government going.

In the same way David Cameron must be grateful he is in a coalition with the Lib Dems and not his rightwing backbenchers, Miliband will not be wanting to rely on support from the likes of Jeremy Corbyn, Dennis Skinner and other members of the "tax and spend" wing of the party to prop up the Government.

He will want a larger majority – as all prime ministers do – and as soon as possible. A snap election will suddenly appear very intoxicating. Harold Wilson saw his majority increase from four to 96 after calling a general election in 1966, fewer than two years after the previous vote. Wilson used the same trick again in 1974, managing to move his government from a minority to a slim majority by calling an October general election just eight months after the February vote.

After two years in government, Miliband will have grown into the role of prime minister. The Labour leader has his critics, but it is remarkable what a bit of power can do for someone’s image. Remember how Cameron and George Osborne were perceived before taking office? How about William Hague? – derided as a joke when Leader of the Opposition but now firmly in the statesman category.

The economy should still be growing. Provided Balls doesn’t balls it up, and sticks broadly to the coalition's spending plans – which he has already alluded to – Labour could reap the benefits of Osborne’s tough line.

If Labour is riding high in the polls, and the feeling is Miliband is about to push the general election button, panicked Tories and Lib Dems will no doubt start to very loudly talk up the Fixed-Term Parliaments Act. But while that Act provided a much-needed and effective anchor on the Con-Lib coalition during its stormier times, there is no reason to suggest Miliband will use it to weigh down the Labour ship. Legally speaking, no parliament can bind another, so it could just be repealed – very easily. Would the Leader of the Opposition (Osborne? Theresa May? Boris?) stand up in parliament and argue against asking the public to vote on a new government?

The Fixed-term Parliaments Act is a complete red herring in all of this. Miliband should go to the polls and increase his majority, like Wilson did in 1966 and 1974. If not, he could end up like Major at the end of his tenure, dragging the government on in the hope something will happen to either destroy the opposition or boost his flagging ratings. Whatever he decides, he must avoid the mistake of the last Labour prime minister, who lost the election-that-never-was in Autumn 2007 simply by not calling one. Brown got the reputation as a ditherer, which haunted him until he left office. As Tony Blair once said, Labour is best when it is boldest. Miliband will do well to emulate the boldness of Wilson, not the dithering of Brown.

Owen Bennett tweets @owenjbennett