Sanjoy Sen is a chemical engineer in North Sea oil. He contested Aberdeen North at the 2015 general election and was a candidate in the Kilburn Ward on Camden in the 2018 London council elections.

Whilst occasionally covering Scottish politics in my previous contributions for this site, I’ve focussed on what I know from my own career: engineering and industry. I’ve never claimed the tag “expert” (and certainly no colleague ever conferred it upon me) but after some 25 years in the energy sector, I would modestly claim some degree of knowledge in this field.

In politics, however, it wasn’t until the Scottish independence referendum that I first took an active interest. So, when discussing election strategy, I’m not writing based on decades of first-hand experience or on meticulous academic research. Instead, I’ll reflect on my own perspectives, not only as a political newcomer but also from when I used to see all this from the outside. How does the stuff political types do resonate with the public?

Compared to some of my earlier pieces, readers may detect a slightly lighter tone. But don’t misread that as flippancy: what is the answer to growing swathes of unwinnable areas and to election stalemates? Come 2022, the Conservatives will have gone 30 years since a decisive general election win – and Labour 17. These are complex times but it sometimes feels that no-one knows how to win over the public anymore.

“I wasn’t going to vote for you, but having read your 10th leaflet…”

Having spent most of my ‘civilian’ life in non-marginals, my personal exposure to election campaigning was (mercifully) minimal. Any leaflets received, however, typically made it from doormat to recycling box in under a minute, earning a skim-read at best. And, of course, I was far from unique: for all the candidates’ efforts, most folks either aren’t voting or are doing so on national issues.

Presumably there’s scientific theory out there proving X per cent of voters will switch once they’ve read Y leaflets, resulting in Z per cent more wins in key marginals. But how reliable is it? Does it factor in punters who loathe your party and receive one communication too many, thus motivating them to get out and vote – for your nearest opponent?

But theory aside, I quickly learned that political types love churning out those leaflets. So I was fascinated to see how this paper-based arms race (in which no-one dare back down) might unfold. First learning point seems to be to discard anywhere deemed unwinnable. Then, blitz the battlegrounds.

Next, there’s leaflet type. Near me in London, Labour went for quality, with fewer but glossier leaflets: punchy messages plus photos of confident-looking candidates. By contrast, Conservatives went for quantity: fewer pics but many more words in each. And as an engineer crunching data daily, I ought to be appalled by the Lib Dems’ horribly skewed bar charts with obligatory “Tories/Labour can’t win here” arrow. But they did look effective. Turned out, however, that despite pitching themselves as the anti-Brexit voice in a strongly Remain area, they failed to break through. Perhaps not so effective, then.

But this isn’t a gripe about leafleting per se: it just reads that way. I, and others, delivered dozens through local letterboxes – that’s what us candidates and volunteers are expected to do. And, in fairness, how many other ways are there of reaching voters directly? Many folks don’t mind expressing their political views freely on social media but aren’t so keen when parties respond to that data.

Instead, I’m more interested in understanding what campaigning can achieve in each area and where to focus limited resources. Beyond a certain point, we’re probably in the law of diminishing returns hitting the same areas over and over again. And that in itself can’t win an election, anyway.

“It’s unwinnable there: forget it”

As Mark Wallace observed, the feared London whitewash in May’s council elections was averted by sound tactics: battlegrounds were identified early then prioritised. It’s encouraging that we can hold our ground especially at a point in the election cycle when the opposition often makes significant gains.

But targeting battlegrounds alone looks increasingly unlikely to deliver a workable majority ever again. We’re already at the point where major cities such as Liverpool, Manchester and Sheffield now feature no Conservative councillors. And demographic changes might soon leave other places unwinnable, such as pretty much any university town.

Everyone understands no party can expect to win everywhere. And resources, especially volunteers, are finite. But focussing on marginals in the short-term and actively working on lost places in the long-term can’t afford to be an either/or decision: it’s difficult to see another election win without both.

Two lessons spring to mind from the Scottish Conservatives. Firstly, don’t give up on places after setbacks: were it not for those 13 hard-won seats last year, we’d be looking at a Corbyn administration right now. And, secondly, respond to the situation. With the SNP not moving on from indyref, Scotland needed a party equally committed to preserving the union.

Scotland might not as unique as some think. Other parts of the UK also feature seemingly impregnable Labour fortresses: but there too, daunting majorities may well be built on shaky foundations. Welsh Labour, in power for 20 years, may well offer the next opportunity as might pro-Brexit northern towns. Here in north London, many in prosperous enclaves see no personal consequences to voting Labour. But at the merest hint of rising taxes or falling property prices, they’ll be re-thinking their position. None of these are going to fall into our lap, though – they’ll take a lot of canvassing and there’ll be setbacks on the way.

Why does this matter?

Had David Cameron picked up just a handful fewer votes in key marginals in 2015, he’d have had no majority. And had Theresa May won just slightly more, she’d have gained a majority. An analogy from us engineers might be to design a bridge with so little margin that just one extra car might (or might not) collapse it. Seems that elections are being fought on margins too narrow to predict let alone influence.

If the Conservatives could have picked the last three Labour leaders, they’d probably have gone with the three Labour went for. But the law of averages, if nothing else, dictates, they’ll eventually pick someone capable of winning an election. Without a strategy to re-engage with lost areas, we might regret missing the opportunities we have right now.