On Thursday, 7 May the people of Britain go to the polls in what promises to be one of the most exhilarating and tense elections in recent memory. With 41 days to go, over the next few weeks we will chart the highs and lows, the pitfalls, the gaffes and goings-on during the campaign. From the inevitable pictures of party leaders hugging unsuspecting children through to the point where one leader will, hopefully, be invited by the Queen to form a government and drive into Downing Street to announce as much, each week we will explore the issues that have dominated the campaign and, perhaps more crucially, provide analysis so as to place events in their wider historical context.

Officially, the campaign period does not begin until Monday. Yet in reality it has been underway for some time. Take, for instance, this past week, where we had two dramatic developments that each in their own way will come to set the scene for the rest of the contest. The first was the surprise announcement by David Cameron during Wednesday’s Prime Minister’s Questions that the Conservatives will not raise VAT if re-elected. The announcement was notably curt for a politician, even more so for a prime minister. And Cameron’s admission was all the more remarkable because it seemed to catch the incredulous looking Labour leader, Ed Miliband, completely off guard. The Chancellor, George Osborne, had after all just the day before refused to completely rule out a rise. Unwilling himself to dismiss rumours of a similar hike in National Insurance during the exchange, Miliband’s Shadow Chancellor, Ed Balls, was then forced to do a round of media to do exactly that. Having now dismissed the principal revenue-raising measures available to government – which, along with income tax account for early two-thirds of all government tax revenue – both leaders will be under even greater pressure to explain quite how they will deal with Britain’s still considerable structural deficit.

The second significant development this week was the appearance of Cameron and Miliband in the first of a series of TV broadcasts. I say ‘broadcasts’ because this was not a debate – the Conservatives had long made clear that the prime minister would not share a stage with Ed Miliband and debate him head-to-head. Instead, each faced individual questioning by Jeremy Paxman, interjected with audience question and answer sessions chaired by Sky’s Kay Burley. Like opinion polls more generally, the view of who ‘won’ on the night was pretty evenly split. A ComRes poll announced immediately after the broadcast gave Cameron a slight edge, but it was by no means convincing. And some opined whether the whole process was balanced against the ‘gloomy’ Labour leader. Like everything, it is a matter of personal taste – for me, Cameron seemed to perform better in the Q&A segment, Miliband remarkably better in the interview with Paxman. Either way, the remaining debates promise to become key moments in the campaign.

And yet, although Parliament has only just formally been dissolved, an enduring theme of this election has seemingly already emerged: that this is a highly unpredictable election, and that the result is more uncertain than any vote in recent times. Unlike previously, so the story goes, simply no one knows what the state of British politics will be on 8 May. This, it is doubtless true, is not 1997. For at least a year before the New Labour landslide Tony Blair managed consistently to poll impressive double-digit leads over his rival, Conservative leader and prime minister John Major. Nor indeed is this 2001, when a New Labour victory was so widely expected that the popular vote fell below 60 per cent for the first time. In fact, this is not really a repeat of 2010, when Gordon Brown’s unpopularity made a Conservative victory of some kind more likely, even if the end result was by no means an overwhelming vindication of ‘Cameronism’.

All that said, I take some issue with this notion of unpredictability. To be clear, I am a historian – I am in the business of examining the past, not predicting the future. But the opinion polls do give us a glimpse of what will likely happen in early May.

• The ‘big two’ will once again reign supreme. A hung parliament is all but inevitable. But despite the rise of the Greens, the Scottish National Party (SNP) and the United Kingdom Independence Party (UKIP), the fight over who will become prime minister will remain a two-way one between Cameron and Miliband.

• I would be willing to bet that the Conservatives will be the largest party on 8 May. The vote, it is certainly true, will be extremely close. But as Lynton Crosby, Cameron’s election ‘guru’, recently said in a briefing to Conservative MPs, in England the party is in fact in a fairly healthy state. According to Crosby, it only needs to gain around 11,200 votes in fewer than 70 seats to win the election outright. This of course is rather easier said that done. But the likelihood of Labour emerging as the biggest party does appear less than the Conservatives coming out as victors.

• Labour will lose big in Scotland – but Miliband may still become prime minister. In one of the quirks of the British electoral system, the largest party, in either seats or number of votes, does not automatically become the party of government. It is the party that can command the confidence of the House of Commons that the monarch invites to establish a government. Take the February 1974 election. Harold Wilson’s Labour party actually won fewer votes than the Conservatives under Edward Heath – some 200,000 votes in all – but gained four more seats and, with it, the ability to create a minority government. And based on the current polls, a centre-left coalition, or a ‘confidence and supply’ arrangement – where there is no formal coalition between parties but a case-by-case arrangement to support key pieces of legislation, such as the government’s budget – may well prove easier for Labour to arrange than the Conservatives.

• The Lib Dems will lose big everywhere. If the 2010 election was the one where everybody agreed with Nick Clegg, the 2015 election will almost certainly be his last as Lib Dem leader. The party is on course to lose around half of its seats and some reports suggest that the tussle over who will replace him is already well underway.

• The SNP will become the ‘third party’ of British politics. Ever since the September 2014 independence referendum the polls have consistently shown that the SNP will probably gain anywhere between 40 and 50 seats in this election, mostly at the expense of Labour. A lot of talk over the last year has been about the rise of UKIP in England, but it is politics north of the border that will decide the fate of parties in Westminster.

• Talking of UKIP, Nigel Farage will not make the breakthrough that some might think. It will almost certainly be the case that the party will increase its current number of MPs. And compared to the last election they will massively improve their returns. But the polls suggest that UKIP’s vote – much like the Green party – is getting squeezed. A recent ComRes poll found the fall to be a remarkable 9 per cent. Of course, the usual advice applies here: it is the trend that is important, not an individual poll. Yet even the trend seems to be against Nigel Farage. The average monthly support for UKIP of nine main pollsters had UKIP support falling three percentage points. For a small party this is huge.

There is, then, a good deal more certainty than many argue. At the very least, the polls tell us the likely parliamentary arithmetic come 8 May. But needless to say, anything could change between now and polling day. The interesting thing for me is not so much who will emerge as king but rather who the king makers will be, the concessions they demand for their acquiescence and the type of system that they employ to support the new monarch. And the polls are unable to show this. It is, to paraphrase Donald Rumsfeld, therefore more a matter of known unknowns than complete unpredictability. Whatever the result, it promises to be an interesting one. And we hope you will join us for the ride.