A referendum is not like an election. While the two sides of the campaign produced lots of literature supporting their view, there wasn’t anything like a manifesto as such. How could there be, given those leading the campaigns were not those who would end up actually implementing the decision? As far as the referendum was concerned, Brexit did indeed just mean Brexit – no more and no less. Nothing on the ballot paper said it was specifically this sort of Brexit or that sort of Brexit.

This has left a certain void, and one that politicians and others have sought to fill. Naturally, they have largely attempted to do so with their pre-existing prejudices rather than evidence. To listen to some it would appear that Brexit was driven by people who wanted {insert policy idea that I wanted to begin with}. A lot of this has been around how important an issue immigration was to Leave voters, and too what extent this was an anti-immigration vote. The alternative argument is often that the vote was mostly driven by concerns about sovereignty and freedom.

At the simplest level, if you want to know why people voted for something… ask them.

In YouGov’s final poll they asked people to pick which one factor was most important to people in deciding how to vote. Among Leave voters the most popular answer was allowing Britain to act independently (45%), followed by immigration (35%) and the economy (8%). Full tabs are here.

Lord Ashcroft’s poll after the referendum asked leave voters to rank four possible reasons for the vote – sovereignty, immigration, the economy or the risk of future EU integration. 49% of Leave voters picked sovereignty as their first reason (78% as either their first or second answer), 33% of Leave voters picked immigration as their first reason (64% as either their first or second reason). These two issues dominate, but the structure of the question suggests that people couldn’t say “I didn’t care about this issue at all”, so its somewhat limited (tabs are here, the relevant questions are on page 256!)

In both of these examples sovereignty came top, followed by immigration. However, it’s possible that this was down to the particular options the pollster offered or the particular wording used in the question. One way of getting round this issue is to ask it as an open-ended question and allow people to say in their own words why they voted as they did – two other polls did this.

In Ipsos-MORI’s final poll they asked what issues would be important to people in deciding how to vote in the referendum, letting people pick more than one option. The interviewer then picked which category or categories matched their answer most closely. In this case immigration came top among Leave voters, picked by 54% (18% also said the cost of immigration on welfare and 12% said the number of refugees coming to Britain – though given people could choose more than one option these cannot be added together). The next highest option among Leave voters was 32% who said the ability of Britain to pass our own laws, followed by 19% who said the economy and 9% who said jobs.

The pre-election wave of the British Election Study did a similar thing, asking respondents to type in what the most important factor driving their vote was and coding it up later. Taking a word cloud of the responses gives one extremely prominent answer…

…but this is actually a little misleading. Once the answers are coded up individually sovereignty comes very narrowly ahead of immigration. Just over 30% of verbatim responses from Leave voters mentioned sovereignty or control in some way, just under 30% mentioned immigration in some way (the word cloud appears as it does because most people who mentioned immigration used the specific word immigration, but people who mentioned sovereignty used a variety of different terms like sovereignty, control, making laws and so on). Suffice to say, immigration and sovereignty were, between them, the main two issues driving the Leave vote.

Referendums and elections are complicated things, and the human beings who vote in them are even more so. Anyone who tries to boil down the referendum to one factor and say “this explains it all” will almost always be wrong. While the order of the two issues differs between polls, all the polling evidence is clear that Leave voters were most concerned about the issues of sovereignty and immigration, and anyone claiming they were motivated by one but not the other is very likely projecting their own views onto the voters.

While they were clearly the dominant issues, there are undoubtedly others too – for example, as John Curtice explores here, there’s a very strong correlation with views on the impact of Brexit on the economy too, so while immigration and sovereignty were strong factors in favour of Leaving, another important factor seems to be that most leave voters did NOT think that Brexit would bring economic damage. I should also give my usual reminder that people are not necessarily very good judges of what makes them vote. We are not particularly rational creatures and the way people vote at referendums and elections is not a dry comparison of policy offers or facts, but often a mixture of vague feelings, bias and heuristics – so things like a lack of trust in the traditional media and “experts” and a perception that the remain campaign were speaking for an out-of-touch establishment rather than ordinary people were probably also factors in driving the Leave vote.

In short – the factors motivating Leave voters are many and varied and 52% of the voters will, by definition, contain people with many, many different views and priorities. However, every effort to ask Leave voters why they voted to leave found sovereignty AND immigration as the clear big issues.

ICM’s latest poll from the Guardian is out, with topline figures of CON 43%(+2), LAB 26%(nc), LDEM 8%(nc), UKIP 11%(-3), GRN 6%(+2) – changes are from ICM’s last poll, conducted for the Sun on Sunday in mid-September.

The seventeen point Conservative lead is the largest that ICM have shown in any poll since October 2009 (the Guardian cites it as the largest since 2008, but I think that’s because they are looking at the ICM/Guardian series of polls – the 2009 poll was one for the News of the World).

The size of the lead is likely flattered by the timing – it was conducted over the weekend, so the Conservatives could have expected some sort of boost from Theresa May’s first conference as leader. It’s also worth noting that ICM do tend to produce some of the most pro-Conservative voting intention figures – they have adopted a substantial number of changes since the polling errors of 2015 (switching to online, weighting by political knowledge, reallocating don’t knows differently and modelling turnout based on age and social class) which tend to produce the most pro-Conservative figures. That’s not to say they are wrong – in 2015 all the pollsters understated the Tory lead, so it’s very likely that in correcting those errors, changes will me made that produce more Conservative figures. We won’t know for sure until 2020 whether pollsters have gone too far in those corrections or not far enough.

In this case, even before the turnout weighting ICM would have been showing a very robust 14 point Conservative lead (and the reallocation of don’t knows actually helped Labour). Whatever you did with this data would have produced a huge great Tory lead – it’s the combination of a new Prime Minister, a Conservative conference boost, and a distracted opposition. Full tabs are here.

A final post on boundary changes (at least until the Scottish proposals next month). This comes from a discussion I had with Mark Pack. Normally the thing we look at with boundary changes is what the party-partisan effect is, how the new boundaries would change the sort of swing that Labour need to win a general election. However, currently Labour are a very, very long way from the sort of polling lead they’d need to win a majority, so a small change in that figure really doesn’t make a lot of difference. More interesting in the current political climate is the effect it would have on Labour internal battle and any potential deselections.

The rules for how Labour will deal with re-selections after boundary changes are yet to be confirmed, so these are based on the rules set out for 2011 in the Labour rule book, on the assumption that Labour’s NEC will use similar rules this time round. A Labour MP has a right to seek selection in any seat that contains 40% or more of the electors in their existing seat. If an MP’s seat is divided up so much that no single seat contains 40% of their old electors then they’ll have the right to seek nomination in a seat with less than 40% of their old voters. If they are the only sitting MP to seek selection in a seat, they are nominated through the normal trigger ballot process. If more than one sitting MP seeks the nomination in a new seat there is a members ballot to pick between them.

Applying those rules to the provisional boundaries we can see where there may be contests under those rules. Note that this list is exhaustive, it contains every case where Labour MPs could compete against each other under the selection rules… but in some cases it will be easily avoided through either agreement (there are enough seats to go round) or retirement (an MP will be well over 70 come the general election and possibly considering retirement anyway). Of the 231 Labour members of Parliament in England & Wales, 142 of them should not face any re-selection difficulties connected to boundary changes – they may well see changes to their seat, but there is a single notionally Labour seat to which they have the sole right to seek selection. What about the other 89?

Avoidable Challenges

There are six places where more than one MP would have a right to seek selection for a seat, but where there are enough Labour seats to go round, so if MPs co-operate and agree between themselves who will stand where, no head-to-head challenge is necessary and no one is left empty handed. These are:
Alfreton and Clay Cross. Nastasha Engel and Dennis Skinner both have the right to seek selection here, but Skinner also has the right to seek selection in Bolsover, so a challenge seems unlikely.
East London. Mike Gapes’ seat is sliced up into tiny pieces, and if the NEC follow past practice he should have the right to seek selection in any of the successor seats. He is the only sitting MP with a right to seek selection in the new, ultra-safe, Forest Gate & Loxford seat so I imagine he will go there. If not, he could challenge Wes Streeting, Margaret Hodge or John Cryer (who could, in turn, seek selection in Stella Creasy’s Walthamstow)
Redcar. Andy McDonald and Anna Turley can both seek selection in Middlesbrough NE & Redcar, but McDonald is also eligible for the safe Middlesbrough W & Stockton E seat, so a challenge is avoidable.
Ashton Under Lyne. Jonathan Reynolds and Angela Rayner are both eligible, but Rayner is also eligible for the safer Failsworth & Droylsden.
Stockport. This is avoidable, but not without some pain for Ann Coffey. Andrew Gwynne & Ann Coffey are both eligible for the safe Stockport North & Denton seat. Ann Coffey is also eligible for the Stockport South & Cheadle seat, but that is far more marginal (that said, Coffey will be 73 at the next election, so may not stand).
Pontefract. Yvette Cooper and Jon Trickett are both eligible to seek selection, but Yvette Cooper also has a free run at Normanton, Castleford and Outwood.

Not Enough Labour seats to go round

The following seven areas have enough seats to go round, but one or more of them is notionally Conservative, so there may be a contest for the winnable seat or someone may be left in a seat that is notionally Conservative:
South London. Siobhain McDonagh’s seat is sliced up. Two of the successor seats, Merton & Wimbledon Common (a potentially winnable marginal) and Sutton & Cheam (no hope) are notionally Conservative, so she will have the choice of fighting one of them, or challenging either Chuka Ummuna or Rosena Allin-Khan.
South-East London. Erith and Thamesmead is split up into Erith & Crayford (a Tory seat) and Woolwich. The only option for a Labour seat for Theresa Pearce is to challenge Matthew Pennycook for the Woolwich nomination. Pennycook has the option of seeking the Woolwich nomination, or going up again Vicky Foxcroft for the Greenwich & Deptford nomination.
Coventry. Geoffrey Robinson’s seat becomes comfortably Conservative on new boundaries, but he has the option of going up against Jim Cunningham for the Coventry South nomination. He’ll be 81 by the next election, so I assume he won’t.
Nottingham. Vernon Coaker’s Gedling seat disappears. Half goes into the Conservative Sherwood seat, so there is the potential of a battle against Chris Leslie for the nomination in the Labour Nottingham East and Carlton seat.
Cumbria. The Workington seat disappears. Part of it goes into the very Conservative Penrith & Solway seat, which is unlikely to be attractive to Sue Hayman, leaving her the option of fighting Jamie Reed for the Whitehaven & Workington seat.
Wrexham. Susan Elan Jones’s Clwyd South seat is dismembered. Part of it goes into the elaborately named De Clwyd a Gogledd Sir Faldwyn seat, but that is notionally Conservative. The other part goes into Wrexham Maelor, where she would have to compete against Ian Lucas for the nomination.
Newport. The Newport seats are combined into one. Jessica Morden would also have the right to seek nomination in Monmouthshire, but that’s solidly Tory leaving one Labour seat between her and Paul Flynn. Flynn will be 85 come the next election, so the issue may well be resolved by retirement.

Straight two way fights

There are seven Labour seats where there are two Labour MPs who are eligible for that seat, and that seat only – meaning a straight fight is unavoidable unless someone stands down:
Sunderland West – Bridget Phillipson vs Sharon Hodgson
Newcastle North West – Catherine McKinnell vs Chi Onwurah
Wednesfield & Willenhall – David Winnick vs Emma Reynolds (though Winnick will be 86)
Stoke South – Rob Flello vs Tristram Hunt
Dudley East & Tipton – Ian Austin vs Adrian Bailey (though Bailey will be 74)
Neath & Aberavon – Stephen Kinnock vs Christina Rees
Cardiff South & East – Jo Stevens vs Stephen Doughty

More complicated fights

There are eight areas where there are rather more complicated fights… but where ultimately there are more Labour MPs than there are seats, so something will have to give:

Birmingham. Roger Godsiff’s seat disppears. He will have the right to seek election in four other Birmingham seats, putting him up against Gisela Stuart, Jess Phillips, Richard Burden or Steve McCabe. He will be 73 come the election though, so may choose to stand down.
Islington & Hackney. The change that got the most attention when the proposals were announced. Essentially Meg Hillier, Jeremy Corbyn, Diane Abbott and Rushanara Ali have to somehow share out the Finsbury Park & Stoke Newington, Hackney West and Bethnal Green and Hackney Central seats. Someone is going to get stuffed.
Rochdale & Bury. Debbie Abrahams, Ivan Lewis, Liz McInnes and Simon Danzcuk are in play, with Rochdale, Prestwich and Middleton and Littleborough & Saddleworth. If Danzcuk remains suspended from the Labour party then the problem presumably resolves itself.
Liverpool. Steve Rotheram’s seat disappears and he would be eligible to challenge Louise Ellman, Peter Dowd or Stephen Twigg for selection in their seats. Rotheram himself is standing for Liverpool mayor, so it won’t be an issue for him. If he steps down though whoever is elected in the subsequent by-election would face the same issue.
Bradford & Leeds. Judith Cummins seat disppears. She is eligible to seek selection for Bradford West (against Naz Shah), in Spen (against Jo Cox’s successor) or in Pudsey, where Rachel Reeves will likely also be seeking the nomination (Leeds West vanishes, but Pudsey takes much of its territory and becomes a notionally Labour seat)
Sheffield. Newly elected Gill Furniss sees her seat dismembered – see is eligible to seek nomination in Sheffield North and Ecclesfield (against Angela Smith) or Sheffield East (against Clive Betts).
Pontypridd. Owen Smith’s seat is dismembered and he will have the right to seek nomination in either Chris Bryant’s Rhondda & Llantrisant or Ann Clwyd’s Cynon Valley and Pontypridd. Ann Clwyd will be 83 by the next election, so it may be resolved by retirement.
Islwyn. Chris Evans’ seat also vanished, and he will have the choice of competing against Nick Smith in Blaenau Gwent or Wayne Davies in Caerphilly.

The deep blue sea

Fourteen Labour MPs do not have a notionally Labour seat they would be eligible to seek selection in. In some cases this is just because of a slight change to an already ultra-marginal seat (e.g. Chris Matheson in Chester notionally loses his seat, but there’s really little change from 2015), in other cases it leaves them with a very difficult fight:

Andy Slaughter would face a Tory majority of 14% in the new Hammersmith & Fulham seat
Gareth Thomas would face a Tory majority of 11% in the new Harrow and Stanmore
Joan Ryan would face a small Tory majority of just 3% in the new Enfield seat
Ruth Cadbury faces a 10% Tory majority in Brentford & Chiswick
Tulip Siddiq faces a 9% Tory majority in Hampstead and Golders Green
Alex Chunningham is only eligible for the nomination in Stockton West, with a 7% Tory majority
Chris Matheson doesn’t actually face much change, but Chester would have a 1% Tory majority on paper
Jenny Chapman faces a notional Tory majority of 1% in Darlington
Madeleine Moon’s Bridgend is merged with the Vale of Glamorgan to create a notionally Tory seat, but with a majority of only 3%
Alan Whitehead’s Southampton Test would have a 4% Tory majority on paper (Southampton Itchen would flip to Labour… but Whitehead doesn’t have the right to go there under Labour rules)
Melanie Orr would be eligible to seek selection in either Grimsby North & Barton or Grimsby South and Cleethorpes. Both, however, would be Conservative.
Holly Walker-Lynch faces a similar situation, under Labour rules she can apply for Calder Valley or Halifax, but they are both notionally Tory.
Finally, in the sorriest situation of all are Margaret Greenwood and Alison McGovern. They are both only eligible to seek selection in the new Bebington & Heswall seat… and even if they do get it, it’s now notionally Tory.

So, by my reckoning there will probably be around 15 re-selection battles where a sitting Labour MP faces up against another sitting Labour MP on the provisional boundaries, though remember that these are subject to change (and it only takes a small adjustment by the boundary commission to shift the number of voters from an old seat above or below 40%). It’s also worth noting that you don’t need boundary changes for a deselection – there is a normal trigger ballot process than can be used to deselect an MP and some of the speculation about deselections – Peter Kyle for example – is not due to Labour seats being merged together.