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Divided kingdom: how England could force a Brexit, even if others vote to stay

Divided kingdom: how England could force a Brexit, even if others vote to stay

Black Zack, CC BY-NC-SA

As the debate over Britain’s future in the European Union gathers pace and heat, there has been much discussion of what might happen if voters in England, Northern Ireland, Scotland and Wales disagree. What if the UK were to leave based on the English vote alone?

Would such an outcome provide the “material change” in circumstances cited by the SNP’s leadership as a potential trigger for a second independence referendum? What would such a decision mean for support for independence in Scotland and Wales? Could there even be implications for the peace deal in Northern Ireland, as the Irish prime minister recently suggested?

At the same time, rather less attention has been paid to the potential for another, equally plausible, outcome. What if England votes narrowly in favour of leaving the EU, but is kept in Europe by its more Europhile UK neighbours? Could such an outcome trigger calls from England for further loosening of ties within the UK?

A nation divisible

All recent survey and polling data confirm that such a gap does indeed exist. Recent polls suggest support for leaving the EU could be as low as 25% in Northern Ireland and 36% in Scotland. In Wales it sits at 45%. Meanwhile, in England, 48% say they would leave (based on averaging recent opinion polls in each country, excluding those who do not know how they will vote).

At the moment then, the polls point to all four countries voting to remain in the EU. But the margin of support for remaining is clearly narrower in England than elsewhere.

Some relatively simple modelling (multiplying the estimated leave vote in each country by that country’s percentage share of the UK population and then summing the totals) enables us to estimate a “tipping point” for votes in England. Above that point, England could take the rest of the UK out of the EU against its will. Below it, and England might be kept in the EU against its will by its neighbours.

The tipping point. NatCen, Author provided

The first thing to note here is that the size of England relative to its neighbours means that a relatively modest majority in favour of leaving there would be enough to outweigh any level of support for remaining in Northern Ireland, Scotland and Wales. If 59.6% of people in England voted to leave the EU, it would be enough to take Britain out of Europe – even if no one in Northern Ireland, Scotland and Wales voted to leave.

However, if we assume that Scotland, Wales and Northern Ireland in fact vote as indicated above (based on the averages of recent polls in each country), then a narrow vote in England in favour of leaving (between 50 and 52.5%) could be overturned by the popularity of staying in the EU elsewhere in the UK. But if more than 52.5% in England voted to leave, the views of those elsewhere in the UK would be outweighed and the UK as a whole would have a majority (just – 50.1%) in favour of leaving.

Turmoil ahead?

Of course, calculating such a tipping point involves a lot of assumptions. The polls in each country would have to be largely correct, for a start, and opinion would have to remain the same up to the vote.

Given the apparent narrowing of the overall lead for the remain campaign in recent polls (our most recent poll of polls puts support across the UK for remaining at just 51%, compared with 49% for leaving), it is feasible that support for leaving could increase across all four nations, and not just in England.

Tweaking the figures to assume a 4 percentage point increase in support for leaving the EU in Scotland, Wales and Northern Ireland reduces the tipping point to 51.7% – if the leave vote in England were above this, then the UK as whole would be tipped in favour of leaving even while Scotland, Wales and Northern Ireland still remained on balance in favour of remaining (albeit only just in Wales in this scenario).

Conversely, if support for leaving the EU fell by 4 percentage points from the figures indicated above in each of Scotland, Wales and Northern Ireland, then at least 53.3% of people in England would need to vote to leave before the UK as a whole would be tipped in favour of leaving.

If the race in England is indeed as tight as current polls suggest, these figures suggest there is considerable potential for the referendum to produce constitutional headaches beyond the specific issue of whether we remain in or leave the EU.