The Secretary of State’s power to call a border poll in Northern Ireland: why British-Irish institutional cooperation is essential

Should there be a referendum on the issue of Irish unification, the Irish government would be expected to play a central role. Etain Tannam argues that Brexit created new tensions in British–Irish relations and has highlighted the need to have firm institutional cooperation between both governments before any referendum is called. As Irish unification would alter greatly the Irish state and the Irish electorate would have to approve of unification by referendum vote, the Irish government’s role is highly significant, even though it has no formal powers in this area in the Belfast/Good Friday Agreement. Moreover, the sensitivity of the unification issue and the need to avoid increasing the sectarian divide imply that longer term management by both governments and joint framing of the issue is required.

The Brexit referendum in 2016 almost immediately reignited the issue of Irish unification, given that a majority of the population in Northern Ireland voted to remain in the EU, including the vast majority of cultural Catholics. The unification issue has surfaced periodically since 2016, though with the exception of Sinn Féin, Irish political parties do not wish to place it on their agendas given its sensitivity. It is clear however that combined with demographic changes in Northern Ireland and the impact of Brexit on support for Scottish independence, there is far more informal discussion of Irish unification than in previous decades. Only the Secretary of State for Northern Ireland has the statutory power to call a referendum on Irish unification, if they perceive there to be evidence of majority support in Northern Ireland for unification. However, in practice, given the fundamental implications for the Irish state and given Irish governments’ role in the peace process and in the Belfast/Good Friday Agreement, the Irish government would be expected to play a central role.

There are many reasons why the Irish government’s role would be crucial. Unification would have complex and wide-ranging impacts on Ireland, necessitating an Irish input into the timing of a referendum on unification. Many referendums could be required to amend the Constitution, dealing with a range of issues, including federalisation of the state and of protection for unionist identity in a new state. 

The intergovernmental process is likely to be fundamental in identifying:

  • Whether the timing is appropriate in both jurisdictions and interpreting whether there is evidence that a majority favours unification. 
  • How to engage with unionists effectively so that a broad consensus emerges and how to devise a strategy that incentivises engagement from unionists and compromise from all parties. 
  • How the debate should be framed gradually to inform the public. 
  • What is the most effective way of ensuring public engagement and what is the appropriate timing to move from elite level discussion to broader engagement, such as Citizens’ Assemblies. 
  • Overall, what is the appropriate balance between British-Irish intergovernmental leadership and the political empowerment of parties and citizens in a devolved Northern Ireland and in Ireland.
  • What constitutional scenarios are more likely to be accepted in both jurisdictions.
  • What constitutional arrangements are possible to implement practically across the territories.

In the absence of joint strategic leadership, the large number of thorny issues implies that any referendum process could be hijacked by domestic political parties with negative consequences for stability. In addition, the process of deciding whether a referendum should occur could be gravely undermined by ad hoc policy making, or by one party holding a balance of power, in the absence of a committed British-Irish long-term policy approach. 

Therefore, British-Irish intergovernmental cooperation is crucial to any future decision-making process. So how can long-term embedded cooperation be ensured? The key lesson from Brexit for British-Irish relations is that informal cooperation does not suffice as it is soon sacrificed if contextual factors change. Despite Irish efforts, Northern Ireland did not feature in the Brexit referendum campaign. The Brexit years have shown how the UK government swayed under DUP and Brexiteer influence and thus show the potential for domestic political pressures to reverse the logic of the peace process. In addition, there are various potential conflicts of interest between both governments. The forthcoming trade talks between the EU and the UK could further divide the Irish and UK governments, for example on the issue of fisheries policy. 

It was precisely because of the potential existence of sensitive, complex and potentially destabilising issues that the British-Irish Intergovernmental Conference (B-IIGC) was a core part of the Belfast/Good Friday Agreement’s institutional architecture. The lesson of the past for both the Irish government and the SDLP led by John Hume was that institutionalised cooperation was essential for effective policy making to Northern Ireland, as otherwise cooperation would wax and wane. For John Hume the EU’s model of institutionalised cooperation, by obliging member states to meet regularly at executive level to compromise and discuss conflicts of interest, was a key factor in Franco-German rapprochement after World War II. The EU framework, by obliging its members to meet regularly increased communication and trust, This logic was emulated in the the Belfast/Good Friday Agreement, with the intention that its institutions would comprise a water-tight system that would survive and manage crises. The Agreement’s Declaration of Support stated that:

It is accepted that all of the institutional and constitutional arrangements – an Assembly in Northern Ireland, a North/South Ministerial Council, implementation bodies, a British-Irish Council and a British-Irish Intergovernmental Conference and any amendments to British Acts of Parliament and the Constitution of Ireland – are interlocking and interdependent.

As regards the B-IIGC , article 5, Strand 3 stated:

In recognition of the Irish Government’s special interest in Northern Ireland and of the extent to which issues of mutual concern arise in relation to Northern Ireland, there will be regular and frequent meetings of the Conference concerned with non-devolved Northern Ireland matters, on which the Irish Government may put forward views and proposals. These meetings, to be co-chaired by the Minister for Foreign Affairs and the Secretary of State for Northern Ireland, would also deal with all-island and cross-border co-operation on non-devolved issues. 

The key to this approach was that it was both long-term and consistent. It began in 1985 with the Anglo-Irish Agreement and contributed to a gradual shift in Ireland from traditional nationalism, whereby Irish unification was a territorial concept and zero sum, to the SDLP-influenced concept of unification of peoples, not territory that eventually would lead to unification with consent across unionist and nationalist communities. The Belfast/Good Friday Agreement was the culmination of this strategic British-Irish intergovernmental approach that began 15 years before the Agreement’s ratification. It is noteworthy that:

  • This approach took 15 years to come to fruition.
  • It occurred after relations became formalised through the Anglo-Irish Conference of the Anglo-Irish Agreement.
  • Its negotiations occurred just after a period of fraught British-Irish relations, following various crises – the Falklands war and H-Block Hunger Strikes, as well as heightened paramilitary violence in England. 

The crises of the early 1980s precipitated the drive to institutionalise relations. The policy makers of the 1980s did not underestimate the challenges they faced in shifting perceptions to embrace a more nuanced perspective of the Northern Ireland conflict in Ireland and in the UK. However, 35 years later, the Brexit period has shown how British-Irish cooperation was less embedded than many thought. 

Overall, whether the Secretary of State interprets that there is evidence of majority support for unification is likely to rest not only on public opinion data, but on a joint framing and planning process by British and Irish governments. It also depends on whether the Irish government perceives evidence of majority support in Ireland for unification. In short, the decision rests on a shared understanding between governments of what will work and will be palatable. A formalised British-Irish process enables the development of that understanding, of a blueprint and of its gradual dissemination to the public over years. The B-IIGC is the obvious forum to develop such cooperation. 

However, its failure to be more central in the Brexit era and generally since 2007 has raised doubts about whether it is fit for purpose and whether British-Irish cooperation should occur in other forums outside the Belfast/Good Friday Agreement. Unionists have long been wary of the B-IIGC, as it gives a consultative role to the Irish government. There were unionist suspicions in the early years of the Agreement that the B-IIGC could be a vehicle for joint UK and Irish sovereignty over Northern Ireland and eventually a path to unification. Nor have most UK governments embraced it. 

The current Tory government would seem very unlikely to warm to it. Thus, the argument is that while institutions may increase international cooperation, a minimal level of political will is a precondition for this multiplier effect. The argument is that if UK political will does not exist, then there are limits to the power of Irish governments to strengthen the B-IIGC and therefore it would need to be replaced, or supplemented. The questions are: is revision of the B-IIGC required and if so, what should be its replacement or supplement? 

Other bilateral institutions exist or have been mentioned. In 2012 the two governments established a bilateral committee comprising heads of UK and Irish civil service departments, the Permanent Secretaries and Secretaries General Group (PSSGG), with a focus on further developing economic relations between Ireland and the UK. Recently, the Taoiseach Leo Varadkar mentioned the possibility of periodic joint Cabinet meetings. References to sectoral bilateral meetings have also been made. However, it is unlikely that these bilateral arrangements would be appropriate for discussion of a unification referendum. The rationale for the PSSGG was to deal with functional policy issues specific to Britain and Ireland, not Northern Ireland issues. A bilateral cabinet meeting would serve the same purpose: to deal with policy issues of relevance to Britain and Ireland and to ensure that networking occurs in the absence of the EU framework. 

A key objection to making the B-IIGC redundant in any way is that dismantling such a key component of the Belfast/Good Friday Agreement could lead to a gradual unpicking of the Agreement. For example, the DUP has also been antipathetic to the North South Ministerial Council that deals with cross-border issues. Thus, protecting the Agreement in all its parts is a key Irish governmental and EU priority. 

Nevertheless the mammoth task ahead of compensating for the loss of networks in the EU implies that resources will be devoted to developing stronger institutional links and networks between the governments. While these have not yet been created, it is possible that the B-IIGC while remaining a core part of the 1998 Agreement could be positioned within these networks. In this way, the B-IIGC and the Agreement remain intact, but exist within a broader framework. It is noteworthy too that the B-IIGC in essence aims to ensure that both governments are in effect guarantors of nationalists’ and unionists’ rights and identities. If there are future discussions of a referendum on unification, it is a potential means of protecting unionist identity and rights. 


The Brexit era has highlighted the need to have firm institutional cooperation between both governments to minimise the chances of miscalculating whether the timing is right for a referendum and to minimise the negative effects of holding one. Although the Secretary of State has the sole statutory power to call a referendum, in practice strategic British-Irish intergovernmental cooperation is crucial. Ensuring that the relationship is more deeply institutionalised by fully utilising the B-IIGC is an appropriate way of guaranteeing that such cooperation occurs. However, given the chicken and egg problem of a minimal level of political will being necessary to allow the B-IIGC play a role, a re-consideration of the B-IIGC’s exact role in the context of possible future East-West institutional arrangements and an emphasis on highlighting its role in protecting unionist identity and rights could make it more palatable to unionists and make it a more effective forum. 

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About the author

Dr Etain Tannam is Associate Professor of International Peace Studies, Trinity College Dublin and a member of the Working Group on Unification Referendums on the Island of Ireland. She is currently writing a book on British–Irish relations in the 21st century, which is to be published by Oxford University Press. 

The views expressed in this post are personal views and do not necessarily reflect those of the Working Group of Unification Referendums on the Island of Ireland as a whole.