The thin red line: It's time for the DUP to accept they have been outmanoeuvred by the Brexiteers

Since the fluke parliamentary arithmetic of the 2017 general election propelled them into the heart of Westminster, the DUP’s relationship with their Conservative party confidence-and-supply partners has often been tense.

Despite public joviality and the professed shared passion for preserving the union, many in the DUP have continued to harbour deep distrust towards their Tory colleagues as they fear the latter’s unionist credentials could ultimately come second to their desire to see Brexit achieved if forced to choose between the two.

As the DUP’s 10 votes in the House of Commons became essential for the prospect of any Brexit deal gaining Westminster backing, the Conservatives have been keen to keep their new partners on side. The DUP’s chief demand has been that there can be no border down the Irish Sea, with their party leader Arlene Foster even going so far as to describe this as a “blood red line” for the unionist party.

What’s more, hardline Brexiteers, including those in the European Research Group, have insisted they could only accept a Brexit deal which would also be palatable to the DUP as well.

Indeed, during the Conservative party leadership contest this summer, Boris Johnson’s close relationship with the DUP and his apparent ability to keep them on side were cited as qualities which would make him a suitable Prime Minister.

It seems, however, that the DUP’s worst fears have now materialised. The new deal announced this week appears to amount to a border down the Irish Sea, with Northern Ireland being subject to different future conditions to the rest of the UK.

While Stormont will have some say over this, the design of the veto will favour Remain parties such as Sinn Féin rather than the DUP.

This is because it will require a simple majority rather than the usual cross-community majority mechanism used in the Northern Ireland Assembly, which would have allowed the DUP to effectively veto changes. As the majority of politicians at Stormont are pro-Remain, this will almost certainly see the parliament opt to continue close alignment with the EU, contrary to the DUP’s wishes.

For staunch unionists like the DUP, different conditions for Northern Ireland and an internal border within the UK amount to an unforgivable undermining of the union and a step towards a united Ireland. The party’s red line has been blatantly breached, despite the Conservatives’ many promises.

Johnson will have known that the deal would be anathema to the DUP, yet announced it regardless in an apparent attempt to “bounce” them into backing it. As the 31st October deadline is a mere fortnight away, many in the UK are desperate to see a no-deal averted. So-called “Brexit fatigue” is also at its height after three years of talks and many members of the public simply want to see politicians get on with it and reach a deal.

As a result, the public’s patience with the DUP will be wearing thin if they are perceived as being the remaining stumbling block to an eleventh-hour deal. Johnson will be hoping that the party will come under unprecedented pressure across the UK to back the proposals for the “greater good” of the union.

Despite this, those familiar with the DUP’s negotiating style will know they are not a party that easily bends to public pressure. Throughout Northern Ireland’s many rounds of Stormont negotiations in recent years, the party has continually prioritised pure ideology and sticking to their word above more pragmatic climb-downs.

It appears that Johnson has calculated that either the DUP will be pressured into backing his deal, or else that their 10 votes no longer hold the same potency they once did. Westminster’s parliamentary arithmetic has shifted many times since the confidence and supply arrangement was first signed in 2017. We have seen the mass withdrawal of the whip from Tory Remainer rebels, as well as indications some Remainer Labour MPs fearful of no-deal could come round to the Prime Minister’s deal, combined with suggestions from hardline ERG members that they could back today’s deal due to fear Brexit could simply never happen if this last opportunity is not taken.

Johnson may, therefore, have calculated that throwing the DUP’s 10 MPs under the proverbial bus could see him garner support from a greater number of MPs from other factions.

Strategically, the DUP may be better advised to publicly back the Brexit deal and argue it is an imperfect pill they will reluctantly swallow for the greater good of the UK in enabling the country to enact Brexit. In doing so, they could save face and could tell their voters at home in Northern Ireland they have still “won” and are acting to preserve the union in a roundabout way.

However, it appears they will not do so. The DUP have been clear in their condemnation of the deal, releasing a statement confirming they will vote against it. This move may have little effect as the Brexit deal could always pass in Westminster regardless, while exposing to the DUP’s voters and the wider UK how the Brexiteers’ lofty claims about preserving the union have now been exposed as hollow. The party stands humiliated and with few palatable options.

Now clearly outmanoeuvred by Johnson and his fellow Brexiteers, the DUP is powerless and betrayed. This betrayal has perhaps been inevitable as their competing demands of a hard Brexit and no border along the Irish Sea or on the island of Ireland have always been incompatible.

Many of the DUP’s opponents will argue they only have themselves to blame in backing Brexit before they knew the consequences for GB-NI relations. The DUP may find the only consolation available to them is to stick to their ideological purity and vote against the deal, even if such a move is practically meaningless.