Dr David Shiels is a Policy Analyst at Open Europe and also works on contemporary political history.

Since the new Brexit deal emerged in October, the relationship between the Conservative Party and unionism in Northern Ireland has been under strain. The Democratic Unionist Party (DUP), along with the smaller Ulster Unionist Party (UUP), are pledging to oppose the new Protocol on Northern Ireland (the replacement for the Backstop). Boris Johnson, who once articulated the unionist case against the original Withdrawal Agreement, has been accused of ditching the Unionists in his hurry to secure a deal.

The narrative that Johnson has betrayed the DUP is a powerful one and suits the purposes of the party’s opponents. Although the nationalist parties oppose Brexit and are more critical of Johnson’s deal than Theresa May’s, they are making the most of the Unionists’ discomfort. In the Republic, the persistent view is that Johnson conceded the EU’s demands, agreeing something like the original Northern Ireland-only backstop. The British Prime Minister certainly altered his red lines on customs arrangements, but it is not unhelpful for Leo Varadkar that Irish commentators are giving more attention to the British concessions than to Ireland’s.

The Taoiseach also moved by agreeing to a consent mechanism on the new Protocol, effectively removing the guarantee that there would never be a hard border in Ireland. The Agreement in theory allows that the Northern Ireland Assembly could overturn the Protocol arrangements in 2024 or later. The DUP complains that this does not respect the principle of cross-community consent but there is nothing to stop them or the Unionist parties together campaigning for a majority in the Assembly, something they had as recently as 2016.

After the referendum, it quickly became clear that Brexit involved a choice between a close EU-UK relationship and a deal allowing for greater EU-UK divergence but with special arrangements for Northern Ireland. The Remain vote in Northern Ireland, the strength of the Irish Government’s position in relation to the EU, and the institutional tendency on the part of the UK to see special treatment for Northern Ireland as normal, were all powerful factors moving against the sort of outcome that the Unionists might have preferred.

In the view of the party’s critics, the DUP is now reaping what it sowed by supporting Leave in 2016. There are signs that the DUP is regretting not voting for the original Withdrawal Agreement. One DUP MP described Johnson’s deal as “worse… than the Agreement that Theresa May brought forward.” But if they wanted a softer Brexit they never articulated it and their alliance with the ERG influenced the debate in the Conservative Party away from such a course of action. A painful break was always possible. The Prime Minister has simply brought forward the decision while securing concessions on the ‘undemocratic’ nature of the Backstop.

Notwithstanding these points, the perception that that Johnson cannot be trusted on the Union may yet seal his political fate. If the Conservatives fall short of an overall majority at the election, they will struggle to convince the DUP to enter into a new confidence and supply arrangement. The DUP could demand he return to Brussels to re-open the deal, a process which would risk a No Deal Brexit. Despite the Unionists’ misgivings about Jeremy Corbyn, some may quietly prefer Corbyn’s alternative plan of a referendum between a soft Brexit and no Brexit. The newly-elected leader of the UUP has said that Remain is better than Johnson’s deal.

A surprising feature of this election in Northern Ireland is the emergence of an informal anti-Brexit pact, which will make a number of DUP seats vulnerable. In South Belfast (a DUP gain from the SDLP in 2017) Sinn Fein are standing aside to give the SDLP a clear run. In North Belfast, held by the DUP’s Nigel Dodds, the SDLP are returning the favour for Sinn Fein, giving anti-abstentionist Remainers an intriguing choice about whether to vote for a candidate who will take his seat to vote the deal down. In East Belfast (which was won by the Alliance Party in 2010 but by the DUP in 2015 and 2017) and North Down (the seat of the retiring independent unionist MP, Lady Hermon) the two nationalist parties are endorsing Alliance, though Alliance is not reciprocating anywhere. The Greens are not standing in these seats and are also endorsing the Remain candidates.

The pact is also a response to the old Unionist arrangement which will see the DUP stand aside for the UUP in Fermanagh and South Tyrone (currently held by Sinn Fein but won by the UUP in 2015) while the UUP will return the favour for Dodds in North Belfast. The NI Conservatives are standing in four seats and the Greens are standing in three seats. Only the Alliance Party is running a candidate in each of the 18 constituencies in Northern Ireland.

To some extent, the anti-Brexit pact is really an anti-DUP pact, and the general election is about scrutinising the DUP’s record in the previous Parliament. On a good day, the DUP might return with ten seats (losing South Belfast but gaining North Down), but the party is very nervous about losing North Belfast to Sinn Fein. On a bad day three of their seats could be vulnerable. As for Sinn Fein, with its abstentionist policy under scrutiny, the party could lose Foyle to the SDLP and Fermanagh and South Tyrone to the UUP. But any increase in the number of Sinn Fein MPs would be a psychological blow to Unionism and would reflect growing disillusionment with Westminster. Unionists are still adjusting to the fact that they can no longer confidently speak as the representatives of the majority voice in Northern Ireland.

Having been unprepared for the consequences of Brexit in the first place, the important thing is that the Unionist parties develop a strategy for the next phase of the negotiations. Indeed, they now have an opportunity to make common cause with business groups and other parties in Northern Ireland as they seek clarifications about how the deal will work in practice.

The fact that there was a visible majority for remaining in the EU in 2016 (and one that appeared to translate into a majority for the Backstop later on) has been disorientating for the DUP. But it may be that many of the voters who gave Northern Ireland a Remain majority in 2016 are constitutionally conservative, and that what they actually want is to maintain the Union with Great Britain as part of the UK while also remaining close to the European Union. The exact balance of that relationship is yet to be worked out, but Unionists should be open to making the new arrangement work.