Bloc Parties

In a world of bloc politics, what's a good offensive strategy?

So here we are. Over the past few weeks a new consensus has emerged about the state of British politics that I hope my recent posts have been a small contributor to. That’s the idea that Britain is shifting into a world of ‘bloc politics’. There is a left-wing ‘bloc’ - Labour, the Greens, the Lib Dems, the SNP and Plaid (and who knows, maybe the so far ill-fated Your Party) and there is a right-wing ‘bloc’ made up out of the Conservatives and Reform UK.

I recognise this is where various people say ho ho ho why is Labour not in the ‘right wing bloc’, they’re just a bunch of authoritarians who hate people on welfare, etc, etc. Now that you have that out of your system, I’ll note that Labour voters at least look very similar to voters from that left bloc, whatever one’s views about Keir Starmer or Shabana Mahmoud. So I’m sticking to this.

There have always been left-leaning and right-leaning parties so what’s with all the ‘bloc’ stuff? The difference is that, according to my colleagues Jane Green and Marta Miori, we are seeing party switching largely confined within those blocs, plus to that most wonderfully mysterious category of Don’t Know.

So Labour voters by and large are not switching to Reform UK (yes, I know some of them are but please read my last three posts on this) but to Don’t Know, to the Lib Dems, and most of all to Zach Polanski’s Greens (about twice as many as to the Greens as to Reform). Similarly, Conservatives are losing their vote base to Reform, not to the Lib Dems (anymore) and certainly not to Labour.

If bloc politics govern voter behaviour, it makes a lot of traditional electoral strategy advice suspect.

In particular it rather undermines the famous ‘median voter’ theory of politics. This theory depicts politics as structured along one single dimension of contestation, usually but not always taxes/spending. The idea is that parties position themselves so as to attract as many voters as possible, with voters choosing parties whose position is closest to their own. Let’s work through this (every day’s a learning day).

Imagine our dimension of politics went between zero and one. If both parties started at the extremes (i.e, the left party at zero and the right party at one) then they would each take the vote of everyone on their side of the line, right up to the middle (0.5).

But that wouldn’t be very strategic. If either party, let’s say our left wing party, moved a bit towards the middle, they would still capture everyone more extreme than them and they will capture some people just right of centre. If our left party positioned itself at 0.2 rather than 0, it would still get everyone whose views were between zero and 0.2, and everyone between 0.2 and 0.5. But what’s new is it would get people with views up to 0.6, because they are indifferent between a party at 0.2 and one at 1.

And now our right wing party realises they will lose, so they shift to 0.8, symmetrically opposite the left wing party’s new position. And things stabilise. Until someone realises they can shift further to the middle and capture new voters for exactly the same reason as before.

And this keeps going until both parties converge on the position of the median voter and ta dah, we have a democracy based around moderate swing voters and parties that don’t really differ from one another…

You will note that this is not a great depiction of our current world so something must be wrong. And political scientists have all kinds of reasons why this model doesn’t fully hold, from uncertainty about voter positions to the inability of parties to credibly commit to policies, to ideology, to abstention, to multi-dimentional politics, etc etc.

But before we throw out the median voter theorem, even if it doesn’t really explain party positioning that well it does help explain both a long run convergence to the preferences of the ‘median voter’ (i.e. policy never gets that far out of line with what they would like… maybe) and electoral strategies that target swing voters as ‘worth double’ because they happily switch between the two main parties.

But it doesn’t work at all if people do not in fact switch between the two main parties. My colleague Tarik Abou-Chadi and his co-authors talk about voters having ‘consideration sets’ - parties they would choose among versus those that are anathema.

In bloc politics, these consideration sets are non-overlapping. Labour, Lib Dem and Green voters won’t vote for Conservatives or Reform. Reform and Conservative voters won’t vote for any of the left parties.

And if that’s the case, median voter style policies - like those that Number 10 seem to have in mind in terms of attracting Reform UK voters… well, they won’t work.

So what’s a strategist to do? Well here’s where the shape of those blocs is crucial. And that takes me back to the infamous/accursed bubble plots of the last few posts.

I did promise no more bubble plots and today’s post will almost keep to that promise. You’ll forgive me, I hope, for riffing off one of the figures from last time and what it means for political campaigning by British parties ahead of the 2029 General Election.

The bubble plot in question was one where I split people answering the May 2025 BES by both vote intention and education group and arrayed them by their preferences on a bunch of economic questions (horizontal access) and a bunch of cultural questions (vertical axis). I’ve explained how I did this in several previous posts so I won’t reiterate here. But I thank Archie Hall from the Economist for making me think a bit more about what this graph shows.

What I want to remind you of is the interesting pattern you see within parties in each bloc. In the left bloc the education divide within each parties is almost completely vertical. So Labour voters who have below GCSE qualifications are more socially conservative than those with A-Levels, who are more socially conservative than those with degrees, especially post-grad ones. The same is true for Green voters. The same is true for Lib Dem voters. And it also looks true for Don’t Knows, which has me believe these are lost ‘left bloc’ voters on the whole.

By contrast among voters in the right bloc, the educational divide is horizontal. Right-leaning voters with higher education are more economically conservative than those with low education, even though their social attitudes are pretty similar. And the bloc as a whole is a long left to right lean with only a mild downward tilt.

So what can we do with this insight?

Back to the political science. Another favourite electoral politics topic for us political scientists is the idea of issue salience and issue ownership. Issue salience refers to the fact that sometimes different dimensions of politics seem more important than others to the debate of the day. So during recessions, economic issues are highly salient. In 2025, it feels like identity questions from immigration to ethnicity have been most salient. Few things are salient forever, otherwise we would still be harping on about regicides and restorationists, or about tariffs on corn (aka wheat). And salience is manipulable by the media and of course by politicians.

And then there’s issue ownership. This is the idea that some parties just have naturally higher favourability on particular issues. So Labour ‘own’ the NHS and public investment, the Conservatives ‘own’ defence and taxes, the Greens ‘own’ the environment, Reform ‘own’ asylum/immigration, and the Lib Dems ‘own’ making your local church’s roof stop leaking.

In general it’s better to try and make more salient the issues you own. This is why Conservatives love Maggie in a tank, or why Labour is at its happiest when Keir Starmer is walking around a hospital.

Back to the bubble plot. If you are a Labour strategist what do you need to do? Well if bloc politics are true, you need to get as many of the left bloc (including current Don’t Knows) to vote for you as possible. And that means you need to find what they have in common, make that salient, especially if you own the issue, and avoid finding something that splits your block, making that salient, and not owning that particular issue.

And what, pray tell, have Labour strategists done? Why, they have made the debate around immigration salient, through draconian new restrictions and breaking promises made to existing immigrants. An issue that splits the left bloc and where Reform, not Labour, ‘own’ the issue. Genius.

An alternative strategy would be to shift the political debate to the economic / public services sphere. I am not saying this would not lead to bad headlines for Labour. Higher taxes absolutely get you bad tabloid headlines. Even just slightly higher taxes. But what it would do is bind your bloc together on mildly centre-left economic policies. You would keep Labour, Lib Dem and Don’t Knows happy and win a bunch of the Greens. You might even win over some Reform voters, though I wouldn’t count on it.

But most importantly you would divide the right bloc. Because Conservative voters really hate higher taxes and spending. And Reform voters? Some do, some don’t. Shifting politics to the economic dimension thus pulls the two right bloc parties apart from one another and keeps both alive. If Reform want to distinguish themselves from the Conservatives they need to promote less neoliberal policies. But those policies will turn off Thatcherite Conservative voters who will stay true blue. If Reform respond by shifting to what I think is probably Farage’s true ideological preference of economically rather conservative policy, well they lose a bunch of poorer and less educated voters.

Oh and on top of which, although Labour don’t ‘own’ taxes (that’s the Tories), they do ‘own’ public spending and NHS, so you make every message about that. Every tax raised is a nurse hired, etc etc. Instead of the current policy which appears to be ‘deport nurses and care workers with too many dependents’.

Similarly if you are Nigel Farage or Kemi Badenoch you want to keep social policies up front on the agenda. This splits the left bloc, making it more likely that members of the right bloc win the 2029 Election. Plus right-wing parties ‘own’ the issue of migration. Highlighting social issues, particularly migration, both splits apart the voter base of each of the left parties and splits the Greens, who in general are most socially liberal, off from everyone else. For those of my subscribers on the right - well done! This is plan is working!

So the current debate is perfect for Reform and the Conservatives. At least it’s perfect for a merger or alliance of some sort. It’s less perfect in terms of who exactly gets to win out in a battle between the two. But since there are minimal differences on social issues, as long as that is the salient public issue, an alliance seems more feasible. And you hold off on a competition to be the leader of the bloc til another day.

In my next Prospect piece, coming out this week OUT NOW, I write about the mismatch between the assumptions made in Rachel Reeves’ budget about economic growth and the fiscal path to 2029 and the draconian immigration rules being introduced by Shabana Mahmood. Crudely, Reeves’ Budget strategy cannot work in tandem with Mahmood’s restrictions. The figures won’t add up.

But there is also a political mismatch. While it’s no soft Labour dream, Reeves’ budget did draw some dividing lines with parties to the right on issues of tax and particularly welfare (scrapping the two child limit). It was more of a ‘real Labour budget’, for good or ill depending on your personal predilections / editors’ views.

It was also a good moment for Kemi Badenoch, since those dividing lines play in her favour - the Tories still ‘owning’ tax policy. Badenoch has been on the up for the past few months and is much more comfortable fighting these traditional battles than following whatever mad new policy Chris Philp or Katie Lam have to exile long-term residents of the country.

If you are Labour, a successful Kemi Badenoch is probably a good thing, since it keeps the split on the right alive. Reform’s strength is not in getting into debates about the Budget with Labour. For example, a few months back Reform also talked about getting rid of the two child benefit cap. Sometimes Reform talk about scrapping every tax they can see, other times about magically keeping benefits high by taxing foreigners, sometimes about how fiscally prudent they will be. Not their best ground.

So, per my point above, with the Budget Labour could finally be tilting politics back onto a dimension that works better for them - a process of reframing that William Riker famously called heresthetics. But in the same few weeks they also decided to announce a myriad of draconian immigration reforms that split apart the left bloc unhelpfully. And they remain deeply confused on other cultural issues from trans rights to Europe.

Every week that Labour aren’t talking about public investment and improving the NHS is a lost week for them. Of course they also have to actually do that. And ideally make good on the promise of a ‘laser-like’ focus on economic growth.

But if you can’t usher a new golden age of British growth - and no-one seems to have been able to since the naughties, when we were talking about rather a different Bloc Party - then you need to get the political fight back on to a playing field you can actually win, that unites voters in your bloc, and divides those in the alternative one.

A regular theme of this blog has been the danger for Labour of targeting all their strategic energy on socially conservative voters who are not interested voting for them. Recent research by Tim Bale, Rob Ford, Paula Surridge, and Will Jennings shows that these so-called ‘hero voters’ Labour targeted in 2024 did not actually turn out for them in any great numbers. So not only are Labour fighting the last war, they are fighting it with a battle-plan that didn’t actually work. It’s Labour’s very own winter invasion of Russia.

Instead of constantly making salient issues that split the left bloc and which Labour emphatically do not own, they would do better to find economic policies that unite their bloc and divide the right bloc. In a world of bloc politics, you need to party with the bloc that brung you.