Unionism – of the plain old, straight-up “United Kingdom of Great Britain and Northern Ireland” kind – is enjoying something of a revival in current British discourse. The primary reason Dominic Raab gave his resignation as Brexit secretary, for example, was framed in terms of unionist unease. The treatment of Northern Ireland in the proposed backstop – the arrangement that will prevail if there is no UK-EU trade deal – he argued, “presents a very real threat to the integrity of the United Kingdom”.

It is curious, then, that article 1 of the text he was supposed to be responsible for negotiating states quite the opposite: “This Protocol respects the … territorial integrity of the United Kingdom.” In international law, the principle of territorial integrity comes under the prohibition of the use of force between states, asserting that the borders of a state should not be altered by violent means.

It is quite remarkable that it was thought necessary or appropriate to underline the inviolability of the territory of the United Kingdom in the legal framework for its withdrawal from the EU. What compelled this and what purpose does it serve, except assurance to those who may claim or fear that it is under threat?

We can be in no doubt that the DUP has had powerful influence in the UK government’s approach to the negotiations. There is little public evidence to suggest it has been proposing alternative ideas or detailed corrections. But its vocal consternation regarding the possible implications of a Northern Ireland-only backstop has clearly left a mark – not just on British discourse and policy, but on the withdrawal agreement itself.

For the latest version of the text is imprinted with efforts to assuage the concerns of unionism – or, at least, how these concerns have been framed by the DUP. The preamble to the protocol now underlines the shared aim of avoiding “controls at the ports and airports of Northern Ireland”, as well as at the Irish land Border. And its very first article directly addresses the constitutional status of Northern Ireland and affirms the “principle of consent” in a manner in tune with the interpretation of “consent” advanced by the DUP in recent months.

Beyond tokenism

Such additions are not merely tokenistic. Most significantly, the new version of the withdrawal agreement has entailed major concession from the EU side in order to allow the inclusion of an all-UK customs arrangement. Contrary to previous indications from Brussels about how far the “flexible and imaginative solutions” could stretch, an all-UK arrangement is now a core part of a backstop. What is more, it will be legally secure on exit and ready for use at the end of the transition period.

The scenario in which the UK stays in a customs union with the EU is outlined in the protocol on Northern Ireland and the Republic. Its primary purpose, therefore, is to avoid a hard border on the island of Ireland. But as an all-UK arrangement, it also minimises the need for checks “in the Irish Sea”.

When she previously described any need for such checks as constituting a threat to the constitutional integrity of the UK, May had made it impossible for unionist parties to support the previous version of the backstop. This new version attempts to bring the DUP back on board, buoyed and protected by an all-UK framework.

But this all-UK backstop also poses a serious test for the newly rediscovered all-UK unionism of the Conservative Party. Most fundamentally, it appears to put it in direct tension with the English nationalism that fired much of the hardline Brexit position. The fact that Raab’s mention of Northern Ireland’s place in the UK was followed by a much longer paragraph bemoaning the all-UK solution suggests that “one for all and all for one” unionism does not run terribly deep. This is why the DUP are far from reassured, of course. It is in the unionists’ lack of trust in British politicians, not Brussels, that the real problems lie.

Other challenges

There are other challenges for unionism, too. As part of the backstop, the protocol allows for a minimal level of regulatory harmonisation between Northern Ireland and the EU necessary for the free movement of goods across the Irish Border, including agricultural produce. It is stressed that this is intended as a temporary arrangement, involving a small fraction of the EU rules that currently apply in Northern Ireland. But the DUP may well believe that its blood-red lines have been drawn too thickly to allow any such differentiation for Northern Ireland – no matter the existing realities of the current internal market of the UK.

And so, while it could quite reasonably trumpet the evidence of its influence on the latest version of the withdrawal agreement, it may yet instead choose to threaten to cut off the hand that has fed it so well.

The party appears to be considering wielding its influence over May’s government in a huge gamble. Make no mistake, the chips in the hand of the DUP in its gamble over a no-deal scenario are valuable indeed. The economy of Northern Ireland. The 1998 Belfast Agreement. Perhaps, unintentionally and somewhat unfortunately, even the “precious union” itself.

And so the party apparently most willing to risk the impact of a no-deal outcome on the United Kingdom of Great Britain and Northern Ireland is the party that both London and Brussels have gone to extraordinary lengths to appease.

Katy Hayward is a Reader in Sociology at Queen’s University Belfast, and Fellow in the Senator George J Mitchell Institute for Global Peace, Security and Justice