Our starting point is that the specific content of referendum campaigns is key to deciding the vote, as are the wider public debates embedding, constraining, and multiplying the messages these campaigns try to convey. This applies to referendums generally, including the 2014 Scottish independence vote and recent referendums on EU matters across the member states. Even if polls show that the voting public favour the EU treaties before the campaigns begin, this initially positive public opinion melts away in some referendums, culminating in rejections. Ece Özlem Atikcan’s research on six different EU referendums since 2005 clearly demonstrates that the campaign – its timing, organisation, and orchestration – is central in determining whether or not this happens.

In addition, political language and argument strategies are particularly important. They can, at least temporarily, reverse public opinion enough to affect referendum outcomes. For example, Claudia Sternberg’s work on narratives involved in the EU’s struggle for legitimacy sheds light on the ways in which campaigns and the surrounding public debates influence or manipulate people’s understandings and perceptions of what is at stake. A number of discursive battlegrounds can become entrenched in the course of the campaigns, and particular associations inextricably linked with EU membership. All this means that the factual basis underlying how the issue is portrayed can become very muddled and appeals to emotions may well end up gaining the upper hand.

In this guest week, as well as our half-day public discussion event at University College London on 8 March, we bring together campaign leaders and activists as well as opinion shapers, media multipliers, commentators, analysts, and academics to examine how the different campaigns out there are trying to affect how people think and how they will vote. We will also consider what lessons may be drawn from other recent referendums that took place both in and outside of the EU. Our aim is twofold: to raise awareness of argument strategies and to critically examine claims made on both sides of the divide about facts. A second guest week, from 21 to 25 March, and second public event on 22 March, will zoom in on one particularly central battleground of the UK debate on EU membership: migration.

Monday

Ece Özlem Atikcan kicks us off by asking what lessons the UK campaigns (and citizens) might learn from the EU referendums held over the past decade. Campaigns, she argues, have been key in deciding, and sometimes swinging, the vote. Drawing on over 160 interviews with campaigners as well as media content and public opinion data, she has found that the key to the puzzle of why public opinion swings in some EU referendums and not in others lies in political campaigns. In a campaign, politicians do not discuss issues objectively. They present issues in particular ways and mobilise voters by encouraging them to think along particular lines. The campaign argumentation strategies of political actors can, at least temporarily, reverse public opinion enough to affect referendum outcomes.

Reflecting on the French rejection the EU’s constitutional treaty in 2005, Renaud Thillaye gives three pieces of advice every Brexit campaigner should take into account. First, he reminds them, voters are well aware that national interest is only ever relative; British membership in the EU is neither a paradise nor a nightmare. Second, the idea of Europe should not be reduced to the EU, and campaigners should discuss credible alternative modes of cooperation with Europe. Such cooperation has always been an important part of British history. Third, it should not be forgotten that the choice is also going to be an emotional one. Campaigners thus need to address how Europe is related to British identity.

Tuesday

Matthew Elliott, the chief executive of Vote Leave, puts forward his organisation’s case for why voters should choose Brexit in the June referendum. “A vote to stay in”, he contends, “will mean a permanent loss of control to Brussels and confirm the supremacy of EU law forever. A vote to leave returns control to the British people, giving us the power to make our own laws and hold the people who make them to account”. Recalling the 2005 debate in France, he posits that an out vote would reclaim agency and sovereignty for Britain. Elliott believes that the British people will – or should – vote leave for three reasons. Brexit would, he contends, defend Britain’s sovereignty to make her own laws; allow Britain to adopt a more ‘humane’ and ‘non-discriminatory’ immigration policy than it can be done within the EU; and remove Britain from a fundamentally unreformable system.

Roland Rudd, treasurer and board member of Britain Stronger in Europe and Chairman of Business for New Europe, presents the other side of the coin and makes the case for keeping the UK in the EU. For Rudd, the question is simple: “do we choose to be stronger, with an economy that creates new opportunities and has the power to shape the future, or do we choose to be weaker, less able to influence global developments that risk harming our economy and compromising our safety?” He identifies two key challenges for the ‘leave’ campaigns, implicitly presenting them as opportunities to the ‘remain’ camp. On the one hand, no one can tell, he argues, what Brexit would actually look like. This makes it impossible for the leave campaigns to present a credible alternative. On the other hand, he highlights the divisions among the ‘leave’ campaigns. These, according to Rudd, run deeper than mere administrative power struggles. The more profound problem they signal is the lack of a common vision for the UK outside of the EU.

The internet and social media have long turned into a key platform and tool for political campaigning, and the UK referendum campaigns around EU membership will be no different. Simon Usherwood and Katharine Wright introduce us to their current research on how the campaigns of both camps have so far unfolded on Twitter. The leave campaigns, they find, have been more dominant in this domain. While both sides of the campaign are putting forward similar themes, the remain camp is not generating nearly as much material that media channels could pick up and amplify. This reduces ‘remain’ groups’ ability to shape the agenda of public debate. In terms of negative campaigning, the leave campaign has the lead, although both sides do use such arguments and not as much as some might think.

Wednesday

The British voters’ decision on Brexit will have significant effects on the whole of the EU, especially in case of a vote for leaving it. But who can speak for the EU in addressing these implications?  Andrew Glencross raises the intriguing question of how EU politicians in other member states should react to the potential Brexit from the European Union. Given the sensitivity of the question, and the possibility of a backlash, pan-European interventions into the UK Brexit debate have so far been rather hesitant. Glencross not only discusses the reasons, but also assesses the various lines that advocates of UK membership in the rest of Europe could take, including the normative commitment to European peace and a persuasive cost-benefit analysis.

Kalypso Nicolaïdis, as a Freek (French and Greek) living and teaching in the UK, addresses her ‘British friends’ in a letter pleading with them to stay in. Her argument does not hinge on the costs and benefits of membership, but on the idea that the EU would be much worse off without Britain. The UK needs to remain in, she proposes, for Europe’s sake, because what is good for the EU is ultimately good for Britain. Her plea is not to abandon a continent in trouble, and to maintain Britain’s traditions of tolerance, common sense, and dynamic vision in the face of ongoing crises including the threat of populism across Europe. The EU, she pleads, would be changed by a British vote to remain, and by a majority declaring themselves In to make it better.

Laura Cram reminds us to think about the Brexit debate in terms of a basic human instinct, the urge to belong to a group. Exploring lessons from social and developmental psychology and cognitive neuroscience, Cram suggests that creating a sense of societal belonging is crucial for the future of the EU and the UK’s place in it. Our capacity to get into the minds of others and understanding what constitutes ‘us’ and ‘them’ in national and EU societies are central to a smooth running European Union. In the upcoming weeks and months, much will be played on whether or not the campaigns succeed in nurturing such feelings of empathy and belonging – and which groups stand out in the perceptions of belonging and self-understandings that will be mobilised most effectively.

Thursday

Drawing on the Irish experience of EU referendums, Joe Costello argues that the Brexit campaign will be crucial to outcome of the referendum. Irish campaigns on the Nice, Lisbon and Fiscal Compact Treaties provide three main lessons. First, campaigners should not be complacent because public opinion does shift over the campaign. Second, people respond better to campaigns involving a wide variety of campaign actors, particularly from the civil society. Third, campaigners should treat referendums as they would general elections and mobilise thorough ground campaigns. Costello also draws our attention to the ‘Celtic fringe of the UK’ – Wales, Scotland and Northern Ireland nationalists who are in favour of continuing EU membership and whose call for independence will surely grow if England alone votes to leave the EU. For Costello, “the presumption that logic and rational argument will carry the day is without foundation”, and the British vote will largely depend on the extent to which Cameron and Johnson front the campaign through bold and sincere leadership.

The 2005 referendums in France and the Netherlands, in the reading of Thijs Berman, were a battle between arrogance and populism. He recounts his experience as a young member of the European Parliament of watching European political leaders close their eyes to the powerful appeal of arguments against the constitutional treaty that gave voice to a strong undercurrent of mistrust, anger and disillusionment. The European leaders’ blindness has been ominous for what has happened since, and for what is culminating in the British vote this summer. Based on Berman’s reading of the EU’s present predicaments, he alerts British campaigners and citizens to three challenges. To begin with, citizens no longer content themselves (if they ever did) with being the spectators and objects of top down policy and decisions, but have to be involved in political will formation. Moreover, his advice to advocates of continued EU membership is to emphasise that governments can no longer stand alone in the face of international challenges of today’s world. It is this internationalisation that leads to the much-deplored ‘loss of sovereignty’ of the EU’s nation-states. The EU, rather than causing the problem, offers tools for mastering it. Finally, the EU needs to reform its ‘rusty’ toolbox of bringing the citizens in. It needs to engage them directly so as to offer effective solutions to these common challenges.

Charlotte Antonsen brings us to the Danish experience with EU referendums, which includes eight votes in the last four decades. Just like the other well-versed EU referendum campaigners, Antonsen warns that people rarely answer the question that is written on the ballot paper. Campaigns almost always bring a new, unexpected dimension of the proposal to the table, and with this new question mark they can easily sway voters. This is especially true when the voters are not familiar with technical EU matters. Her seven concrete pieces of advice to Brexit campaigners are to make it a simple question, to focus the campaign on one main question, to keep the campaign short, to time the referendum well, to allow non-politicians to debate, to be concrete about what the consequences of the vote would be, and never to wear blue socks with yellow stars!

Ece Özlem Atikcan is an Assistant Professor at the Department of Political Science at Université Laval in Quebec, Canada, and an Visiting Senior Research Associate at the UCL European Institute.

Claudia Sternberg is a Senior Research Associate at the UCL European Institute.

This piece is co-published on openDemocracy, as part of our guest week there.

Note: The views expressed in this post are those of the author, and not of the UCL European Institute, nor of UCL.