Michael Dowsett is a Conservative Party activist and a former Vice-Chairman of Southampton University Conservative Association.

The foundational argument behind both the Blair and Cameron modernisation projects within their respective parties was simple: elections are won, or lost, in the centre ground of British politics. The third New Labour general election victory in May 2005 and the clear election of David Cameron to lead his party as a centrist “modern, compassionate Conservative” in December of the same year seemed to consolidate the position of the highly electorally coveted, often undecided, centre-ground voter at the heart of British politics.

However, over the course of the current Parliament; with the formation of the Coalition Government; the resulting defection of large numbers of Liberal Democrat voters to Ed Miliband’s Labour Party; and the annexation of a large number of Conservative voters by UKIP; a new analysis has emerged. This new analysis contends that the next election will not be won by voters switching between Labour and the Conservatives – a trend which has been to varying degrees a key feature of every post-war UK general election – but instead will be primarily a battle fought on the political flanks between Labour and the Liberal Democrats on the left, and the Conservatives and UKIP on the right.

This analysis has permeated further into the psyches of the Labour and Conservative leaderships over the last eighteen months or so than would have seemed possible before 2010. The increasing Conservative focus during 2013 on controlling immigration, restricting welfare and offering an EU referendum are all clearly calibrated towards trying to hold the Party’s core vote together on the right. Meanwhile, Miliband’s recent embrace of explicitly statist prescriptions to try to ease popular concerns over the cost of living clearly flows, at least in part, from a strategic decision to assemble a winning electoral coalition to the left of New Labour’s.

However, despite the decline in prominence which undecided, broadly centrist voters have experienced over the last few years in the minds of the main political parties and the commentariat, opinion polling, especially since the party conference season, shows that this group is still likely to play the central role in deciding the next government.

For example, a recent YouGov poll, which gave Labour a six point (40 per cent to 34 per cent) lead over the Conservatives, showed that nearly 12 per cent of Conservative voters from last time around intended to vote UKIP in 2015, whilst around 28 per cent of Liberal Democrat voters from 2010 said that they were intending to back Labour next time around. These two groups of voters, which have respectively been the subject of much political commentary over the last year or two together comprise, on the data above, approximately one tenth of the UK electorate.

However, recent polling also shows a number of smaller trends within the electorate which suggest that the next election is still likely to be decided, to a large extent, in the political centre rather than on the left and right flanks of politics. For example, the same YouGov poll cited above which shows the Conservatives at 34 per cent, two per-cent below the 36 per cent they scored in 2010, also shows the Conservatives attracting the support of over 10 per cent of 2010 Liberal Democrat voters, alongside around 6 per cent of voters who opted for Labour in 2010.

These less reported developments, especially the defection of former Labour voters to the Conservatives since 2010, not only emphasise the high number of contestable voters in the centre, but also shows that Miliband’s post-conference season rise in the opinion polls has been achieved through a consolidation of his existing coalition of tribal, centre-left Labour supporters and socially democratic former Liberal Democrats. As such, Mr Miliband remains vulnerable to an electorally savvy David Cameron (or Nick Clegg) harvesting less tribal voters who stuck with Gordon Brown last time.

These two electoral groups described in the previous paragraph, along with the smaller number of voters who have switched from the Conservatives to either Labour or the Liberal Democrats since 2010, together form approximately six per cent of the UK electorate. However, when factoring in the number of Conservative voters from 2010 who are currently undecided about their choice next time, this figure rises significantly to around 11 per cent of the electorate. Going further, and factoring in currently undecided Labour and Liberal Democrat voters, at least some of whom are likely to be open to voting Conservative, raises this figure still further to almost one fifth of the electorate.

Furthermore, a typical undecided voter in Britain in 2013 is around twice as likely to be female than male, and is most likely to be aged between 25-39 years old: both groups which have seen some of the steepest declines in Conservative support since 2010.

Given the above observations, the leaders of the main political parties seem certain to enter the next general election campaign facing one of the most fragmented electorates in decades. With traditional party loyalties in decline, both Cameron and Clegg face the challenge of attempting to shore up their bases on the right and left respectively, whilst also seeking to maximise their appeal to the centre. Meanwhile, Miliband seems stuck between adhering to a strategy focused on his ideological comfort zone, and the need to reach out to more moderate voters who he will need if he is to win a clear mandate next time around.

One thing is for certain though: the fragmentation of the electorate on both the centre-left and centre-right should be seen as emerging alongside, rather than supplanting, the crucial group of voters in the centre who have long decided elections in the UK. The challenge for all of the main party leaders will be to craft a message and a vision of where they see Britain at the end of the current decade which appeals to both their wavering traditional supporters and uncommitted voters in the centre.

Developments over the next eighteen months will help to demonstrate whether this is possible, but should in no way diminish the central role which the political centre-ground will once again play in determining who walks up Downing Street in May 2015.