I was intrigued by a recent article by John Harris for The Guardian, in which he set out his reasons as to why the left was allegedly failing across Europe.

All over the west, the left is in crisis. It cannot find answers to three urgent problems: the disruptive force of globalisation, the rise of populist nationalism, and the decline of traditional work.

Harris for the most part looks at the intellectual and human reasons why the left is failing, but I was interested in just how much this is happening in hard poll numbers. Perhaps the centre-left titans of old are now zombie parties, but if people keep voting for them then nonetheless the zombies will continue standing.

Harris alludes quickly to a decline in polling – but let’s have a closer look.

I decided to trawl through the electoral archives to plot the fortunes of the primary centre-left party for six major European nations. This is in parliamentary elections, and is from 1945 (or an appropriate starting point thereafter) to the present day and beyond.

So there it is.

First of all, an apology. Because virtually every centre-left party insists on some shade of red as their party colour, I was forced to use fairly generic colouring scheme here.

But secondly, look at that post-2000 decline. With the exception of the Socialist party in France, every party has declined significantly since then. It seems unlikely that any of these parties will break 40% again, or even 30%, in the near future. Some, such as the Social Democrats in Sweden, have suffered a long, protracted decline. The Spanish Socialist Workers’ Party seems to be the only one that has had a sudden collapse in support. Every party has peaks and troughs, but this is clearly something else across Europe.

I calculated the median results for all parties in a second graph. Where there were multiple elections for a nation within the allocated time-frames, I averaged the result out between them to prevent multiple elections dragging the graph in one direction.

This simplifies that somewhat noisy chart. What is highlighted here is a notable trough from 1985-1994, before a bounce afterwards. Is this likely again? Probably not. Many have claimed the crises experienced by the centre-left today are far worse than in the 80’s.

But what about the right? Are they too in a crisis of support?

Again, the colour here isn’t important, but it is worth noting a change in colour denotes a change in primary party.

The centre-right has apparently taken a hit, but it seems nothing compared to the left. What’s more, many centre-right parties look set to increase their vote-share in the next election. There is a problem with the centre-right in many countries – many are losing their support to populist right-wing parties such as UKIP and FN. But to say that their problems resemble the left is clearly an overstatement.

Finally, let’s compare those median results together now.

It’s worth noting several things before accepting these. First, clearly, I am not a statistician. There are a number of areas where these graphs could be misleading. For example, not every centre-left party is exactly the same. Some may be further left than others or part of a parliamentary coalition. Does Corbyn’s current Labour count as centre left, for example? The relative absence of results in early years may also skew them slightly – though I have tried my best to include accurate opinion polling data for the post-2016 dates.

If this data was presented on its own then I may say that we need more investigation. But it isn’t: it supports a claim rather than makes one. And that claim is a very serious one. Across the West, the left is declining. Will the far-left take their place? Will the far-right rise?

I intend to investigate these questions by looking at the data for these parties in a later post. For now, let the focus be on these parties. What will halt their stalling vote-share? It’s not my job to say. History tells us they can recover. But it seems increasingly unlikely that they will be able to any time soon.