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Labour’s lead isn’t what it seems The national polls are exaggerating Starmer's lead

(Belinda Jiao/Getty Images)


May 23, 2024   6 mins

Within minutes of an election being called yesterday, the question on every broadcaster’s lips wasn’t whether the Conservative Party would lose in July — but how damaging the margin will be.

Labour’s current lead has a very wide range among pollsters, from 15 points (J.L. Partners) to 27 (YouGov). And yet, this does not tell the entire story: at the local elections, the BBC’s Projected National Vote (PNV) share pointed towards a single-figure lead for Keir Starmer’s party. So, as we stare down the barrel of a new election campaign, what explains these large gaps — and what is Labour’s “true” lead?

To answer this, Focaldata used this month’s local elections to project a general election result. And our findings may surprise you. They suggest that, for all the excitement emanating from Labour quarters yesterday, their popular vote is much lower than national polling estimates. However, thanks in large part to the efficient nature of the party’s current vote distribution, we believe Labour is still on course for a large parliamentary majority: we estimate that Labour needs a 5-7% vote-share lead to win, the lowest the party has needed to clear since 2010.

What is Labour’s “true” lead?

In the recent local elections, Labour’s lead over the Conservatives in the PNV share was nine points, with Keir Starmer’s party on 34% and Rishi Sunak’s on 25%. This is a much smaller lead than estimated by national polls.

However, local election PNVs are not necessarily a useful metric for assessing how the country might vote in a general election. There is, history shows, very little relationship between the PNV in the set of local elections preceding a general election and the subsequent result. Our analysis of the past 10 general elections shows no provable relationship between local election PNV lead and final popular vote margin.

That being said, we think that the PNV is likely to be much closer to Labour’s “true” lead. National vote intention polls are “nowcasts” — glassy snapshots of current opinion — rather than forecasts of actual voting behaviour in a general election. Many assumptions that pollsters make to turn their polls into forecasts, including how they treat “don’t knows” and handle turnout effects, could be playing up Labour’s lead. In the month leading up to the local elections, for example, different pollster methodologies accounted for a full four percentage point difference in Labour’s vote share.

To better understand Labour’s “true” lead, FocalData, inspired by the work of Dylan Difford, compared the local election results to historic data on local-to-general election voting behaviour from the British Election Study. For the seats where we did not have a complete picture from the locals, we used the results from the latest public MRP polls.

As you can see from the table above, a significant chunk of Liberal Democrat and Green local election voters said they intended to vote for Labour in a general election. We thus allocated 30% of Lib Dem voters and 34% of Greens to the Labour column in our projection.

This locals-to-general election transition model produced a Labour lead of 12 points in Great Britain, with the party on course for a majority of around 140 seats (394 seats for Labour vs 160 for the Conservatives). At the national level, our projection puts Labour on 38%, the Conservatives on 26%, the Lib Dems on 13%, Reform on 7% and the Greens on 5%.

The efficiency of Labour’s vote

The second important story that emerged from the local elections relates to vote efficiency: the likelihood of a supporter to actually vote. If we take our local-to-general election projection and group Conservative and Labour-held seats based on their partisanship compared to the national average, we find that the Conservative-to-Labour swing is much higher in Conservative-held seats. In other words, Labour are winning votes exactly in the places it needs to form a majority government.

To examine vote efficiency in more detail, we started with Colin Rallings and Michael Thrasher’s estimates of the notional results for the 2019 general election on new constituency boundaries. To estimate the outcome if the national popular vote was tied between the two main parties, all seats not held by the Conservatives or Labour were removed and each constituency was adjusted via a uniform national swing. Seats with a more than 25-point gap between the two parties were designated as “safe” and those with a 10–25-point gap were designated as “lean”, with all others marked as battleground seats. As you can see below, Labour appears to be winning over voters exactly where it needs to, with proportionally larger swings projected in the safest Conservative seats.

An important side effect of better-distributed voters will be a huge increase in the number of marginal seats at the next election. The chart below shows all seats ordered by marginality in 2019, along with our 2024 locals projection. The number of seats with a winning margin smaller than five points has more than trebled, from 56 in 2019 to an estimated 175 in 2024. While we expect some of this tight distribution to be an artifacts of MRP modelling, there is no doubt that this election will see seats in play that have not been in more than 20 years.

The implication of this is that any movement in the polls between now and the election is likely to have an outsized effect on the number of seats won by each party. While we project a sizeable majority for Labour, the window of possible outcomes is wide.

What does Labour’s lead need to be?

As a result of its increased vote efficiency, it seems unlikely Labour will need a double-figure popular-vote lead for a majority. Even so, the exact size of the necessary Conservative-Labour gap remains a point of disagreement among analysts and commentators — and with good cause. The popular-vote lead needed for a majority, for either party, has changed dramatically over the last 45 years.

So much could be written about the graph above. Looking at the 1992 election, Labour needed a popular-vote lead of only 0.6 points to govern (which is what the polls were showing), but the Conservatives needed a large 6.7-point voting gap. By contrast, in 2001, Labour could have governed the country with a majority despite being three points behind the Conservatives. The Blair years saw some of the most unequal, unrepresentative governments to have been elected in Britain, on increasingly depressed turnout levels.

“Big majorities assembled at warp speed seem to look more like sandcastles than skyscrapers.”

As for what it needs to be this time, there are a number of factors that benefit Labour: from their advantageous distribution in marginal seats to the likelihood of the Lib Dems taking seats off the Tories. In particular, tactical voting will be particularly significant: for there appears to be much more Labour/Liberal Democrat tactical voting under Starmer’s leadership than there was under Jeremy Corbyn. This is understandable when we consider that 2019 Lib Dem voters rated Starmer an average of 5.4 out of 10 in the most recent British Election Study survey, versus 2.6 for Corbyn — the highest gap between the two men of any party. In fact, 2019 Liberal Democrats are basically indistinguishable from 2019 Labour voters in their opinions on the current Labour leader (the latter rated Starmer an average of 5.5 out of 10).

How will this benefit Labour? The exhibit below shows the level of efficiency of the Labour/Liberal Democrat vote share. From our analysis, there is an increasing pattern of the two parties’ voters aligning themselves with the strongest anti-Conservative challenger in subsequent elections. This pattern has also emerged in by-elections over the course of this parliament, and would reduce Labour’s majority threshold even further if replicated at a general election.

And yet, despite this highly optimistic outlook for Labour, we must declare a word of warning: as mentioned, the window of probable electoral outcomes is large, and all the dynamics which are likely to propel Labour to a sizeable majority could become unstuck very quickly. Any combination of the Conservatives appealing to cultural Conservatives and older voters again, an SNP recovery, and southern free-market Liberal Democrat voters unable to cope with a period of high-tax Labour government, could cause significant problems for Keir Starmer. In today’s day and age, big majorities assembled at warp speed seem to look more like sandcastles than skyscrapers.


James Kanagasooriam is a partner at Hanbury Strategy and an advisory board member of the think tank Onward.

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Right-Wing Hippie
Right-Wing Hippie
27 days ago

The only poll that matters is the one on election day.

Peter B
Peter B
27 days ago

Based on recent elections, it seems fair to assume that the political pundits will be wrong in their complacent assumptions again. It’s just not possible to know just how wrong they’ll be and in what direction yet.
I’d like to challenge myself to switch off all broadcast media political coverage for the next 6 weeks and only watch the results on the night. I’ll never do it, but think of all the time that could be saved and better used.

Champagne Socialist
Champagne Socialist
27 days ago

Wishful thinking, chums!
July will be an historic wipeout for the Tories – and richly deserved.
Two of the three prime ministers in this parliament will go down as amongst the very worst that Britain has ever seen. No-one will remember the third.
Prepare yourself for the sunlit uplands of Labour governments for a generation!

Lancashire Lad
Lancashire Lad
27 days ago

Shouldn’t that be gaslit uplands?

Ian Barton
Ian Barton
27 days ago
Reply to  Lancashire Lad

Gas will not be allowed under Labour.

Peter B
Peter B
27 days ago

I think you’d be wise to wait a few more years to see how well your lot perform before issuing the league tables.
But then you’re a socialist, so history is whatever you say it is !

John Dellingby
John Dellingby
27 days ago

Yay for more unsustainable immigration, pandering to every divisive minority cause, self-flagellation on nationality, net zero on steroids and no radical change whatsoever. Can’t wait to see the state of our democracy in 4-5 years time.

Mike Michaels
Mike Michaels
27 days ago
Reply to  John Dellingby

There will be no democracy in five years. The fake conservatives performance over the last five years was designed solely to ensure that Davos man/kneeler would be in place to deliver our country safely into the arms of Agenda 2030. All going to plan nicely.

John Dellingby
John Dellingby
27 days ago

I’d say that Labour’s lead is not as it seems, simply because there is no enthusiasm for them. The Tories deserve the public humiliation they’ve got coming, but let’s not pretend that Starmer is going to be cheered into Downing Street. I’ll be amazed if turnout is above 60%.

Hugh Bryant
Hugh Bryant
26 days ago
Reply to  John Dellingby

It all depends on how long Labour can go on simply not telling the truth about the climate, gender and immigration policies that they will inevitable introduce. I think there’s going to be a lot of buyer’s remorse as these become clear.

Tyler Durden
Tyler Durden
26 days ago

No, it’s a large anti-Tory vote on the table which doesn’t necessarily translate into the biggest Labour majority ever.
Sir Keir is even more insipid than Rishi and 6 weeks is more than enough time for the British public to become completely sick of the Briton most destined to be PM (after Boris).

Bill Bailey
Bill Bailey
26 days ago
Reply to  Tyler Durden

Election night will be boring by about 2am when both parties are trying to explain why they couldn’t achieve what they claimed. The good news is that when the election AFTER comes, given both parties insane desire to decarbonise the grid rapidly. We won’t have any power to broadcast it.

Dougie Undersub
Dougie Undersub
26 days ago

Thank God I’ll be on holiday for much of June.

UnHerd Reader
UnHerd Reader
26 days ago

I never understood why Lib Dem voters think that Labour is preferable to Tories, I mean Labour is far more illiberal (in the original Classical Liberal sense not the Americanised version) and anti freedom.

I suspect that the Libs have become a blancmange centrist canvas now and no one knows what they really stand for anymore – certainly the old Whiggish sensibilities are long gone and the SDP part of Lib Dems seems firmly in charge now with Wera Hobhouse making it clear in recent years that voters should indeed tactically vote for labour and the Lib dems voting for the atrociously illiberal Hate Crime Bill in Scotland

We truly have very little choice these days…the least worst of a load of terrible options

Simon Denis
Simon Denis
22 days ago
Reply to  UnHerd Reader

Excellent comment – but I would apply your diagnosis to the Conservatives, too. The trouble is, people are adding Labour to this list of mushy centrists when they are in fact hard left. It seems to me, then, that this cannot be an election of positive choice; neither can it be an election of indifference – staying at home, spoiling the ballot, voting Green or Reform. No, it must be an election of negation – whom, then, to negate? Why, Starmer, naturally; and that means a vote for that floundering imbecile, Sunak. The trouble is, people are very unused to voting in this negative spirit. They have been indulged by all sorts of activism and political rage – PR, Scotland, Brexit, “Get Brexit Done” etcetera and they have forgotten that life is largely a choice of evils. With an evil as clear and horrible as Starmer in view, let us hope they recall this point in time. After all, using Sunak to stop Starmer today in no way prevents us from using the subsequent reprieve to set up a real challenge from the right – and under FPTP this can only be done constituency by constituency. Finally, to all those thinking that a Reform vote is the answer, such as the plump and fruity historian who works for the NCF, I say this: your own diagnosis – “right wing voters are dying at a rate of two per cent a year” – means that the nuclear of option of “let Starmer show them how awful the left can be – is a non-starter. The indoctrinated, bought up, apathetic populace of today will never, repeat never rebel. The very fact that so many are planning to spoil the paper or stay at home means that rebellion is off their radar. So the “lesser of two evils” argument is – quite literally – our only hope.

Simon Blanchard
Simon Blanchard
26 days ago

Well I’m a Labour voter but they’re going to win anyway so I’m going to vote Reform in my safe Tory constituency. Probably. My vote is irrelevant.

Tyler Durden
Tyler Durden
22 days ago

Unbelievably insipid, Sir Keir, ripe only for leadership by Washington neocons and the European Central Bank in Frankfurt.