Why is British politics so fragmented?

Last week's seven-way election debate probably didn't do much to sway opinions about the British political elites.

Predictably, the leaders of the smaller and regional parties spoke passionately and, for the most part well, about their particular concerns. They had the luxury, though, of having no national record to defend.

Nick Clegg attempted to set up the LibDems as the balancing force between Tory cuts and Labour spending, with one eye on a possible future coalition. David Cameron did not clearly lose the debate - or his cool - as some felt he might. And Ed Miliband didn't storm the barricades, choosing to focus on specific policy issues rather than providing a captivating vision for the prefered future.

Whomever the pundits now deign to be the best performers, the event did underline an important question that will likely dog British elections for years to come: Will any political party ever again command a mandate to govern on its own? Will any party leader ever again speak with authority to and for a constituency beyond their own members and committed supporters?

In a 2014 speech in Ottawa, Georg Milbradt, the former Premier and Finance Minister of the German state of Saxony, remarked that 'the Euro is a currency in search of its state'. Are Britain's major political groups now reduced to parties in search of national constituencies?

Is British politics so fragmented that coalitions and minority governments have already become the status quo? If so, why can't the parties build support bases that are broad and deep?

Arguably a number of factors contribute to the fragmentation we're seeing in political engagement. Some of them have to do with purely political processes like devolution. The Welsh and Scots were well represented in this evening's debaate, as they should be - though it was perhaps surprising that the DUP was excluded so that Northern Ireland had no distinctive voice.

However, there are non-political reasons for teh fragmentation, too. Among them is the rapid growth of urbanisation. Every week, according to some estimates, one million people move into the cities of the world. Right now, 51 percent of the globe lives in cities and by 2050, if current trends continue, 75 percent of us will be urban dwellers.

Urbanisation throws together large numbers of people, drawn from different ethnic and socio-economic backgrounds, and asks them to find common cause with each other. Yet social cohesion requires a sense of shared identity and narrative.

Human beings find security in a certain degree of uniformity, which means that city-dwellers (that is, most of us) must now look for identity outside of the immediate physical community. This messes with local political loyalties. Single-party allegiance once helped to define local cultures; now, loyalty is more often to vaguely defined ideas.

Some of the fragmentation in our politics has to do with our consumerist mindset. An arguably more self-centric approach to lifestyles in the post-war consumer age has produced a more eclectic outlook on politics.

Brand loyalty is a thing of the past. When we shop for food, clothing or entertainment, we mix-and-match. We experiment with new permutations and combinations in the hope of discovering some stimulating new experience.