Speaking in the House of Commons, the Prime Minister described the controversial provisions of the UK Internal Market (UKIM) Bill as a “legal safety net” to protect “the Northern Irish peace process and the Good Friday Agreement” against “extreme” implementation of the Ireland/Northern Ireland Protocol (the Protocol) contained in the UK-EU Withdrawal Agreement that he signed last year. Speaking after an extraordinary meeting of the UK-EU Joint Committee overseeing the implementation of the Withdrawal Agreement, European Commission Vice-President, Maroš Šefčovič explicitly rejected the Prime Minister’s argument stating that the UKIM “does the opposite” by undermining the Protocol which has, as its aim, protection of the peace process in Northern Ireland and the much discussed Belfast or Good Friday Agreement (‘the 1998 Agreement’).
How is it that opposing parties can invoke the same agreement to justify their conflicting positions?
One of the great triumphs of the 1998 Agreement is its internal ‘constructive ambiguity’ on issues of national identity and the constitutional aspirations of the people of Northern Ireland. By embracing an ‘extra conventional’ constitutionalism, it allowed consensus between opposing communities in Northern Ireland to be built on the basis of an agreement about means without resolving their dispute about ends. One of the less triumphant characteristics of the 1998 Agreement, however, is its external unconstructive ambiguity regarding its legal or political status. In short, there are two ways to interpret the 1998 Agreement, one that gives primacy to its political or moral status and another that rather emphasises its legal basis in an international treaty. In light of the provisions set out in the UKIM Bill, this ambiguity is likely to come before the courts in future litigations should sections 41 and 42 of the UKIM be used to enact measures to implement the Protocol in ways that some argue contradict the 1998 Agreement.
It is, therefore, prescient to consider the different ways in which the 1998 Agreement is defined and interpreted in advance of any such legal action.
1998 Agreement Entry into Force
To understand the current dispute, it is necessary to examine the circumstances in which the 1998 Agreement was created. Signed on 10 April 1998, the Agreement has two parts: a political agreement agreed between political parties in Northern Ireland (the ‘Multi-Party Agreement’) and an international treaty between the governments of the United Kingdom and Ireland (the ‘British-Irish Agreement’) who act as ‘guarantors’ to the substance of the Multi-Party Agreement. Although widely known by the day it was signed, the terms of the Agreement did not take effect in UK law until the 2 December 1999 after a series of legal actions, set out in the Multi-Party Agreement (Validation, Implementation and Review s11) had taken place.
Ten days after the agreement was signed, then Secretary of State for Northern Ireland, Mo Mowlam, laid it before Parliament in Command Paper 3883 – in substance, a copy of the draft political agreement between parties in Northern Ireland with an as yet unratified bilateral treaty between the UK and Ireland attached as an annex.
On 22 May 1998 concurrent referenda were held in Northern Ireland and the Republic of Ireland to approve the terms of the 1998 Agreement as they would apply in the two jurisdictions on the island of Ireland. After this, and in accordance with a 71% ‘yes’ vote in Northern Ireland, the majority of the substance of the Multi-Party Agreement was translated into UK law via the Northern Ireland Act (1998 Act); this received royal assent on 19 November 1998.
At the same time, and in accordance with the 94% ‘yes’ vote in the Republic of Ireland, four supplementary bilateral treaties were signed by the Secretary of State for Northern Ireland and the Irish Minister for Foreign Affairs on 8 March 1999 to establish: implementation bodies for cross-border cooperation (Cm 4293), the North-South Ministerial Council (Cm 4294), the British-Irish Intergovernmental Conference (Cm 4295) and the British Irish Council (Cm 4296) as set out in the 1998 Agreement.
Following all of the above, the text signed on Good Friday in 1998 was laid before the House of Commons again in March 1999, this time by the Secretary of State for Foreign and Commonwealth Affairs, as Command Paper 4292 – in substance, a now ratified bilateral treaty between the UK and Ireland with a copy of the political agreement between parties in Northern Ireland, underpinned by popular consent, attached as an annex.
Two definitions of the 1998 Agreement
So, in effect, two versions of the same 1998 Agreement were laid before the UK Parliament; in substance they are identical but in structure and status they differ. In the earlier, unconfirmed and unratified version (Cm 3883), primacy is given to the political Multi-Party Agreement; in the later, confirmed and ratified version (Cm4292), primacy is given to the legal bilateral treaty, the British-Irish Agreement.
UK law defines the “Belfast Agreement” as “the agreement reached at multi-party talks on Northern Ireland set out in Command Paper 3883” (Northern Ireland Act, 1998: s98); the earlier version with the political agreement more prominent than the unratified, annexed British-Irish Agreement. The definition of the 1998 Agreement in the UK-EU Withdrawal Agreement corresponds to the later confirmed and ratified version, but it also contains a modicum of ambiguity. The Protocol Preamble describes:
…the Good Friday or Belfast Agreement of 10 April 1998 between the Government of the United Kingdom, the Government of Ireland and the other participants in the multi-party negotiations (the ‘1998 Agreement’), which is annexed to the British-Irish Agreement of the same date (the ‘British-Irish Agreement’), including its subsequent implementation agreements and arrangements[2019, recital 4].
The structure – multi-party agreement annexed to bilateral treaty – reflects the later Cm 4292 version, indeed, the language used echoes the preamble of the British-Irish Agreement; yet, there is some confusion in the description of the ‘1998 Agreement’ as between the two governments as well as the “other participants”. In the Preamble to the Multi-Party Agreement, “the participants” explicitly “endorse the commitment made by the British and Irish Governments” set out in the British-Irish Agreement. As such, the two governments were not ‘participants’ in the Multi-Party Agreement and neither, of course, were the political parties ‘participants’ in the British-Irish Agreement.
In view of the sequence of events between April 1998 and March 1999, the Withdrawal Agreement definition is somewhat of a catch-all. Reference to the two governments participation on Good Friday 1998 is an indication that the bilateral treaty is included in the ‘1998 Agreement’ but, by stating that the ‘1998 Agreement’ as defined is annexed to the ‘British-Irish Agreement’ the Withdrawal Agreement definition is clearly based on the later ratified and confirmed version which is lodged as an international treaty with the United Nations and is, properly understood, legally binding.
The 1998 Agreement in Miller  and Robinson 
Why does any of this matter? For two reasons: first, it exemplifies a problematic ambiguity that surrounds the legal and political basis of the widely invoked 1998 Agreement and the still-in-process peace it represents; second, given that the row that has erupted over the UKIM Bill is likely to lead to legal proceedings in which the Belfast or Good Friday or 1998 Agreement will be central, clarity over its status and requirements could not be more important.
In R (Miller) v Secretary of State for Exiting the European Union (‘Miller’) the Supreme Court was asked to determine if provisions of the 1998 Act “read together with the Belfast Agreement and the British-Irish Agreement”  placed any constraint on executive power to trigger article 50 of the Treaty on the European Union (‘Article 50’). While the Court acknowledged the 1998 Act to be “the product of” the 1998 Agreement and a “very important step” in the peace process which established institutions and arrangements to “address the unique political history of the province” it proceeded to ignore that history by interpreting the question only through the lens of its “relevant commonality” with devolution arrangements in Scotland and Wales . Having already determined in their deliberations on the “main issue”  in Miller that primary legislation would be required prior to triggering Article 50, the Court determined “it [was] not necessary to reach a definitive view on the first referred question”  concerning constraints placed by the 1998 Agreement and 1998 Act on the executive’s use of prerogative power. The ‘unique political history’, cited in but ignored by the Court in Miller, sets Northern Ireland as a constitutional place apart in ways that are of pressing relevance to contemporary political machinations yet are not often subject to detailed scrutiny.
By way of demonstration, on the specific matter of the exercise of prerogative powers that was before the Court in Miller, the Interpretation Act (Northern Ireland) 1954 states that the Crown is “not bound, unless named”; section 7 of the 1954 Act states:
No enactment passed or made after the commencement of this Act shall bind or affect in any manner whatsoever Her Majesty or Her Majesty’s rights or prerogatives, unless it is stated therein that Her Majesty is bound thereby to the full extent authorized or permitted by the constitutional laws of Northern Ireland or to such less extent as is specified in the enactment.(emphasis added)
Such language of ‘constitutional laws’ is unusual in UK legislation, which only serves to demonstrates the extent of Northern Ireland’s domestic constitutional distinctiveness. To underline the point, in Robinson v. Secretary of State for Northern Ireland the 1998 Act was judicially recognised to be “in effect a constitution” for Northern Ireland  and one that ought to be interpreted in line with the principles laid down in the 1998 Agreement. The Robinson ruling reinforced Northern Ireland’s distinctiveness as a UK region with the majority of its ‘constitutional laws’ codified in a single piece of legislation deriving from an international agreement; the approach of the Court in Miller seemed to row back from such an understanding of the 1998 Act as constitutional but, in their own terms, the view expressed was not “definitive” [Miller, 132].
Conclusion: Unconstructive Ambiguity
In view of the EU’s threat to take legal action against the UK over its proposals to disapply aspects of the Protocol designed to protect the 1998 Agreement it is extremely likely that the status of that agreement, variously understood, will be central in forthcoming, controversial legal cases. By including aspects of the 1998 Agreement in the Protocol – namely EU citizenship rights for Irish citizens (Protocol, Article 2) and North-South cooperation (Protocol, Article 11) – these have been granted a new international legal weight accompanied by a nuanced system for oversight (Protocol, Article 12 – 15) and remedy (Withdrawal Agreement, Article 167 – 181). Consequently, the way in which the 1998 Agreement is legally defined and politically understood in the UK is crucial; at present, it is cloaked in an ambiguity that is unconstructive and, from a Northern Ireland perspective, potentially dangerous.
If the 1998 Agreement is understood in the UK as merely a political agreement it may be judicially unenforceable; if it is understood in the EU as a UK-Ireland treaty, certain provisions of which are underpinned by an EU-UK treaty, it will be judicially enforceable. Which means, the dispute over the UKIM is probably only the start.
The author is grateful to the editors for helpful comments on earlier drafts.
Lisa Claire Whitten is a PhD candidate at Queen’s University Belfast, researching the impact of Brexit on the constitution of Northern Ireland.
(Suggested citation: L. C. Whitten, ‘The Belfast ‘Good Friday’ Agreement & Unconstructive Ambiguity’, U.K. Const. L. Blog 16th Sept. 2020) (available at https://ukconstitutionallaw.org/))