by Dr Adrian Worton
We're back with our breakdown of individual party prospects. We've already seen how bleak things look for the Conservatives, with the majority of predictions putting them in the region of roughly 110-130 seats.
But could it get any worse? Both the Liberal Democrats and Reform UK have been touted as possibly overtaking the Conservatives in July and becoming the official opposition. We will use our model to see if this is realistic.
We're back with our breakdown of individual party prospects. We've already seen how bleak things look for the Conservatives, with the majority of predictions putting them in the region of roughly 110-130 seats.
But could it get any worse? Both the Liberal Democrats and Reform UK have been touted as possibly overtaking the Conservatives in July and becoming the official opposition. We will use our model to see if this is realistic.
Note: the odds data in this article was collected on the 19th June, used in our latest seat projections.
Background
British politics has been a two-horse race for over a century, with the Conservatives and Labour finishing 1st and 2nd in some order in every election since 1922. And, if anything, their co-dominance only seemed to be increasing in recent years. For example, the 2017 election saw their highest combined vote share since 1970. Two years later the Conservatives recorded their highest-ever number of votes, whilst Labour's total votes was actually their third-highest total since the turn of the Millenium.
So why is this duopoly now under threat?
Well, the Conservatives are collapsing in the polls. At the time of the election being called they were polling somewhere between 25-30%. They dropped a bit after the announcement, but the hammer blow was Nigel Farage's decision to become leader of Reform and stand in Clacton. Since then Reform have gone from around 10% to around 18% in the polls, with their rise almost exactly mirrored by a decline in Conservative support. At time of writing they are struggling to keep their vote share above 20%.
Below is the BBC's aggregate poll tracker:
Background
British politics has been a two-horse race for over a century, with the Conservatives and Labour finishing 1st and 2nd in some order in every election since 1922. And, if anything, their co-dominance only seemed to be increasing in recent years. For example, the 2017 election saw their highest combined vote share since 1970. Two years later the Conservatives recorded their highest-ever number of votes, whilst Labour's total votes was actually their third-highest total since the turn of the Millenium.
So why is this duopoly now under threat?
Well, the Conservatives are collapsing in the polls. At the time of the election being called they were polling somewhere between 25-30%. They dropped a bit after the announcement, but the hammer blow was Nigel Farage's decision to become leader of Reform and stand in Clacton. Since then Reform have gone from around 10% to around 18% in the polls, with their rise almost exactly mirrored by a decline in Conservative support. At time of writing they are struggling to keep their vote share above 20%.
Below is the BBC's aggregate poll tracker:
In terms of pure polling numbers, Reform are clearly the third party in the country, with a realistic chance of finishing second. But being third isn't enough to guarantee many seats; UKIP finished third in 2015 with 12.6% of the vote and earned just 1 MP.
At the moment most seat projections have Reform on under half a dozen seats. But their trajectory doesn't show any sign of slowing down and if it continues there will be a tipping point when they suddenly start taking swathes of seats from the Conservatives. And if we get to that point where seat projections are showing Reform rapidly gaining seats, then it could cause another tipping point among voters who had been planning to vote Conservative because they see them as the better electoral bet.
It is a slightly different story for the Lib Dems. They do seem to have taken intended votes away from Labour - when the election was called Labour were polling at over 45% and the Lib Dems were below 10%. Now, the Lib Dems are up a few points, polling at around 13%, whilst Labour are down a few points and are hovering around 40% [footnote 1].
But despite polling below Reform, every single seat projection tracked by Wikipedia has the Lib Dems on dozens of seats. They range from 23-67 compared to Reform's 0-5.
Vote spread
How can the Liberal Democrats poll so low and take so many seats? The key is in how their votes are distributed. Below are histograms for the projected vote share of them and Reform, as per YouGov's recent MRP:
At the moment most seat projections have Reform on under half a dozen seats. But their trajectory doesn't show any sign of slowing down and if it continues there will be a tipping point when they suddenly start taking swathes of seats from the Conservatives. And if we get to that point where seat projections are showing Reform rapidly gaining seats, then it could cause another tipping point among voters who had been planning to vote Conservative because they see them as the better electoral bet.
It is a slightly different story for the Lib Dems. They do seem to have taken intended votes away from Labour - when the election was called Labour were polling at over 45% and the Lib Dems were below 10%. Now, the Lib Dems are up a few points, polling at around 13%, whilst Labour are down a few points and are hovering around 40% [footnote 1].
But despite polling below Reform, every single seat projection tracked by Wikipedia has the Lib Dems on dozens of seats. They range from 23-67 compared to Reform's 0-5.
Vote spread
How can the Liberal Democrats poll so low and take so many seats? The key is in how their votes are distributed. Below are histograms for the projected vote share of them and Reform, as per YouGov's recent MRP:
Reform's histogram looks better, because the Lib Dems' seats peak at around 5% whilst Reform's peak is just above 15%.
Unfortunately for Reform, you do not win seats with 15% of the vote in a constituency. You do not even win seats with double that. Below is a histogram of the winning vote share of every constituency at the last election:
Unfortunately for Reform, you do not win seats with 15% of the vote in a constituency. You do not even win seats with double that. Below is a histogram of the winning vote share of every constituency at the last election:
The lowest share was Sinn Féin's South Down victory, with 32.4%. Labour's Sheffield Hallam win is the only other seat won with under 35% and indeed only 21 took under 40%. Most winning candidates took over 50% of the vote in their constituency.
Generally speaking, we can say that a vote share of over 40% is where your start winning seats.
If we return to the Lib Dem and Reform histograms above, we can see that the Lib Dem distribution has a long tail trailing to the right of the chart. Those are a selection of seats where they have a high vote share, and in total there are 41 seats where YouGov are predicting the Lib Dems to take over 40% of the vote. By contrast, there is just one seat where Reform are projected meet this threshold (Clacton, 45%).
So this is how the Lib Dems record a high number of seats compared to Reform, and how Reform can poll so well but may only take 1 seat.
Whether or not it is a deliberate strategy, the Lib Dems clearly have focused their message to maximise their vote in target seats, at the expense of seats elsewhere. This does perhaps set a ceiling on the Lib Dems' aspirations, given the large number of seats where they have little-to-no chance. YouGov estimate the Lib Dem as receiving 10% or less of the vote in 470 of the 650 constituencies.
By contrast, there is arguably a greater upside to Reform's distribution. Because their appeal is clearly pretty universal across the UK's constituencies (i.e. they have a consistent projected vote share), then if their polling improves then they will suddenly have a big chunk of seats where they can win.
Our model
The model we have developed, using bookmaker odds, is much colder on Reform. Below is the two parties' beeswarm charts (explained in our Labour article here):
Generally speaking, we can say that a vote share of over 40% is where your start winning seats.
If we return to the Lib Dem and Reform histograms above, we can see that the Lib Dem distribution has a long tail trailing to the right of the chart. Those are a selection of seats where they have a high vote share, and in total there are 41 seats where YouGov are predicting the Lib Dems to take over 40% of the vote. By contrast, there is just one seat where Reform are projected meet this threshold (Clacton, 45%).
So this is how the Lib Dems record a high number of seats compared to Reform, and how Reform can poll so well but may only take 1 seat.
Whether or not it is a deliberate strategy, the Lib Dems clearly have focused their message to maximise their vote in target seats, at the expense of seats elsewhere. This does perhaps set a ceiling on the Lib Dems' aspirations, given the large number of seats where they have little-to-no chance. YouGov estimate the Lib Dem as receiving 10% or less of the vote in 470 of the 650 constituencies.
By contrast, there is arguably a greater upside to Reform's distribution. Because their appeal is clearly pretty universal across the UK's constituencies (i.e. they have a consistent projected vote share), then if their polling improves then they will suddenly have a big chunk of seats where they can win.
Our model
The model we have developed, using bookmaker odds, is much colder on Reform. Below is the two parties' beeswarm charts (explained in our Labour article here):
We deemed a total success rate (also defined in the Labour article above) of 10-90% to be plausible. If we plot the number of seats each party earns for success rates in this range, we get:
Under this method, the best-case scenario for the Lib Dems is that they reach 77 seats (where the success level is 10%). They just need a success level of 25% to get over 70 seats, and 40% to beat their General Election record of 62.
But for Reform their best-case scenario is 6, and any success rate above 40% sees them take just Clacton.
6 clearly isn't enough to become the next Opposition, but can the Liberal Democrats overtake the Conservatives? On our article on the latter we found that the Conservatives could face a big drop-off in seats if they under-perform the polls even a little. A success rate of around 63% would see their seat count in the mid-70s.
Therefore, it really doesn't take a big leap from the current positions for the Conservatives to end up in the same range as the Lib Dems - say between 65-75, if the latter over-perform and the Conservatives under-perform. So there is a plausible chance the Lib Dems could end up the second-largest party on the 5th of July.
Summary
A analysis of both our odds-based model and polls suggest that talk of a new opposition party is not completely unreasonable. But despite Reform's surge in the polls, it is the Liberal Democrats who are best-placed to swoop in.
The distribution of Lib Dem votes casts a natural ceiling on their potential performance, but with the Conservative vote imploding the non-Labour votes are getting highly fractured, and that opens up an opportunity for the Lib Dems. In a typical General Election with two main parties performing adequately, there would be a large gap before the Lib Dems.
For Reform, the picture is completely different. Their cross-country appeal hinders them as they are only near the winning line in a handful of seats. But if they keep growing in the polls they will suddenly have a lot of seats where they can challenge.
But for Reform their best-case scenario is 6, and any success rate above 40% sees them take just Clacton.
6 clearly isn't enough to become the next Opposition, but can the Liberal Democrats overtake the Conservatives? On our article on the latter we found that the Conservatives could face a big drop-off in seats if they under-perform the polls even a little. A success rate of around 63% would see their seat count in the mid-70s.
Therefore, it really doesn't take a big leap from the current positions for the Conservatives to end up in the same range as the Lib Dems - say between 65-75, if the latter over-perform and the Conservatives under-perform. So there is a plausible chance the Lib Dems could end up the second-largest party on the 5th of July.
Summary
A analysis of both our odds-based model and polls suggest that talk of a new opposition party is not completely unreasonable. But despite Reform's surge in the polls, it is the Liberal Democrats who are best-placed to swoop in.
The distribution of Lib Dem votes casts a natural ceiling on their potential performance, but with the Conservative vote imploding the non-Labour votes are getting highly fractured, and that opens up an opportunity for the Lib Dems. In a typical General Election with two main parties performing adequately, there would be a large gap before the Lib Dems.
For Reform, the picture is completely different. Their cross-country appeal hinders them as they are only near the winning line in a handful of seats. But if they keep growing in the polls they will suddenly have a lot of seats where they can challenge.
Footnotes:
[1]
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A word on Labour's vote share: some polls have had Labour below 40% of the vote share, whilst still projecting a landslide. For example, YouGov's 19th June MRP gives Labour 425 seats whilst their 17-18th June polling gives them 36% of the national vote share.
This really, really, really shows a lot about First Past the Post (FPTP). Labour took 40.0% of the vote in 2017, and whilst it was seen as a relative success it was still only just enough to deny the Conservatives a majority. It is hard to comprehend how Labour could finish several points below their 2017 performance and receive over 100 more seats. This is the reason that it's hard to see FPTP going anywhere. A more proportional system would likely have benefitted Labour in the 2010s, but now the foot is firmly on the other foot. I personally believe it's hard to argue that FPTP is good for democracy, but on the plus side it is much more fun to model mathematically! |