It is hard to doubt the unionist credentials of Wallace Thompson. For one thing, he is a founding member of the Democratic Unionist Party, a party that has made its name as unflinching guardians of Northern Ireland’s place in the United Kingdom. But recent events were, he said, “almost enough to make me question the value of the Union”.

The draft Brexit deal negotiated by Boris Johnson is widely seen in Northern Ireland as a disaster for unionism. And the fact that the DUP had propped this government up since 2017, lending the Conservatives its 10 MPs, makes it feel like a particularly acute betrayal.

Why this story? A question that came up in recent ThinkIns – both in Belfast and London – was how the DUP got into this mess. The DUP are hard to read and not forthcoming. But Sam McBride is the political editor of the Belfast News Letter, the leading unionist newspaper. There is no-one better who could answer that question. Chris Cook, Editor Read more Read less

When it was brought to the House of Commons, not a single Tory MP voted with the DUP against Johnson’s proposed deal. Not a single MP with the whip of the so-called “Conservative and Unionist Party” objected to the proposal, which would involve Northern Ireland not just remaining tied to much EU regulation after the rest of the UK leaves the EU, but also put new checks in place on goods passing between Great Britain and Northern Ireland.

The speed and comprehensiveness of the DUP’s betrayal by Johnson and his party has stunned DUP figures. Friends had warned Thompson, a former DUP special adviser, not to trust the Tories, “but I genuinely did believe that [Johnson] and his colleagues would stand by Northern Ireland,” he said. “Ultimately most Tories simply use unionists and then dump them from a great height when it suits. It has always been thus. Will we never learn?”

Echoing the words of Northern Ireland’s founding father, Lord Carson, about how he felt used as a pawn by London and then abandoned, he added: “What a fool I was. History should have alerted me to this pattern of betrayal.”

Boris Johnson and Arlene Foster stand side-by-side at the Democratic Unionist Party's annual conference in 2018

This loss of faith from a veteran unionist is remarkable and reflects the astounding speed of the destabilisation of Northern Ireland’s position in the UK. Just four years ago, Northern Ireland was more stable and more constitutionally secure than it had been in decades. The document known as the Belfast Agreement – or Good Friday Agreement – had won consent for the status quo even from nationalists.

But now the unionist tradition faces existential threats. This month has seen a brutal reminder – once again – that much of the population of England cares little for Northern Ireland’s place within the Union. If the deal passes, it will make the link to Great Britain weaker. And all in the name of Brexit, a project which the DUP supported wholeheartedly. This is a crisis for unionism with deep roots in the DUP’s history.

Ian Paisley was an ambitious man. He wanted to, and ultimately did, both lead unionism and become Northern Ireland’s First Minister. But when he founded the Protestant Unionist Party in 1966, Paisley could not have believed that his entry into politics would influence the course of European history.

The DUP's founder, Ian Paisley, leads a demonstration from Trafalgar Square to Downing Street in London, 1967

The fiery 40-year-old preacher was the archetypal outsider. Not only was he setting up a rival to the Official Unionist Party, the force which for the first 50 years of Northern Ireland’s existence had shaped and run the north-eastern corner of Ireland as a de facto one-party state, but he had also set up his own religious denomination just 15 years earlier.

The Free Presbyterian Church grew rapidly, snapping at the heels of the huge Presbyterian Church and asserting that the faith which the Protestant settlers had brought with them from Scotland 350 years earlier was being heretically reshaped by the Presbyterian establishment – especially in ecumenical moves towards inter-faith dialogue with the Roman Catholic Church.

Faith, politics and the constitutional link to Britain had for centuries been so entwined in Ireland – and especially in Ulster – that there was a logic to Paisley taking his religious critique of the Protestant religious establishment and applying it to the unionist political establishment.

The Official Unionist Party had been so dominant that between 1929 and 1965 it held 29 of Stormont’s 48 constituencies, almost two thirds of which were never even contested in that period. Some of its seats were held thanks to gerrymandering to make it harder for nationalists to win.

But such dominance produced a flabby party which, outside of some left-wing or localised independent unionist challenges, was not used to working hard for votes.

Paisley, a charismatic natural leader and a gifted orator, was initially viewed by some within the Stormont government as a booming cleric who would simply be an irritant.

Paisley preaches his political creed in Belfast, 1972

But, as well as being a zealot, he was a pragmatist, and within five years of founding the Protestant Unionist Party, Paisley had replaced it with the Democratic Unionist Party. The new political vehicle was dominated by its founder, who would remain in post until forced out almost 37 years later, by which time the octogenarian Paisley was First Minister.

But, from the outset, the DUP has been an insular and greatly misunderstood party, often poor at explaining itself to those beyond its natural hinterland and fiercely resistant to claims that it has changed position.

For example, the DUP was subtly less religiously exclusive than Paisley’s first foray into politics and incorporated those who did not share Paisley’s religious views – most notably the exceptionally gifted QC Desmond Boal who defined the new party as “right wing in the sense of being strong on the constitution, but to the left on social issues”.

Few people realised it at the time – and, to this day, the DUP is seen by many of its critics as ideologically theocratic. But the party had from the outset been built to be a secular party seeking to appeal to the greatest possible mass of the electorate.

That was not always obvious: while the DUP was a secular party, it was always headily infused with religious messages. Paisley would preach politics from the pulpit of his vast Martyrs’ Memorial church on Belfast’s Ravenhill Road – and talk religion in seemingly unending speeches to the DUP’s annual conference.

The sociologist Steve Bruce, whose largely sympathetic biography of Paisley is one of the most detailed attempts at understanding an exceptionally complex and contradictory figure, says in that work that if Paisley had to be compressed into just two propositions, strong candidates would be “I am doing God’s will” and “You cannot trust the elite”.

As Margaret Thatcher delivers a speech at the European Parliament, Paisley makes his position clear

One of the most lurid intersections of politics and religion was in his view of the European Union. Not only did Paisley oppose the EU on nationalistic grounds, he also saw it literally in apocalyptic terms.

Paisley spoke of the EU as a “satanic” force. As late as 1998, he was describing the EU as “a beast ridden by the harlot Catholic church, conspiring to create a Europe controlled by the Vatican”.

Only a minority of DUP members today would sign up to such a proposition and instead largely oppose the pan-European project for reasons familiar to Eurosceptics across the UK – loss of sovereignty, bureaucracy, and, in some cases, nostalgia. But that deep hostility to Brussels has been a constant since the party’s founding.

The moment when I realised that the DUP was going to come out for the Leave side in the referendum came on Arlene Foster’s first day as First Minister in January 2016.

As a former Ulster Unionist, Foster was not steeped in DUP history. As a business minister in the Stormont Executive, she had seemed particularly open to working with the EU. However, for months before she took over, the party’s arch-Brexiteer Sammy Wilson had been increasingly outspoken about the need to quit the EU and had been showing up at rallies with Nigel Farage – despite his party leadership saying that it had not yet decided which side to back in the referendum.

He had also considered running for the DUP leadership before outgoing leader Peter Robinson had cleared the way for Foster to succeed him without a contest and there were rumours of bad blood between the pair.

Arlene Foster poses for photographers after becoming First Minister in 2016

When, sitting in Foster’s Parliament Buildings’ office at Stormont, I asked her which side the DUP would back in the looming referendum, the new First Minister was cautious, as I had expected, and said that the party would not “prejudge” David Cameron’s attempt to renegotiate the UK’s terms of EU membership.

That was in stark contrast to pro-EU parties in Northern Ireland, such as the SDLP and Alliance, and also in contrast to the staunchly Eurosceptic Traditional Unionist Voice and UKIP, which had been gradually establishing a base in Northern Ireland.

But Foster’s next answer surprised me, because it made clear that she would back Leave in the referendum.

When asked if she could adopt a policy such as Cameron’s, where his ministers were allowed to campaign either to leave the EU or to stay in the EU, Foster was robustly clear, saying that the DUP would “definitely take a position” as a party.

Given the DUP’s history, it would have been impossible for it to have endorsed staying in the EU on the first opportunity it had been given to enact its anti-EU ideology. Therefore, it was clear that, regardless of Cameron’s renegotiation, the party would be advocating a Leave vote.

It would be a few weeks before that decision was formally enacted. Academic research by Mary C Murphy and Jonathan Evershed of University College Cork sheds further light on what went on around that period. Their report quoted an unattributable interview with a DUP member of the Northern Ireland assembly who recalled: “I was at the policy-making conference that we had – I say conference, it was a meeting upstairs – where they said, ‘right gentlemen, we need to agree our policy on Brexit’ – this was before the referendum. And 10 minutes later we had agreed our policy. We just went round the room and it was, ‘Burn it! Shoot it! Strangle it!’”

The academics formed the view that “the DUP’s coming out for leave was as much a matter of party management and political expediency as of ideological principle” and that an unprepared leadership never expected to win. Multiple DUP sources, some of whom were discreetly in favour of Remain, have privately endorsed that analysis.

Sammy Wilson, a DUP MP, leads the celebrations for the Leave campaign in 2016

It was the expectation of defeat in the referendum that explains its lack of a plan and some of the incoherence of the party’s positions since then.

Just a day before the EU referendum, a DUP special adviser to the Agriculture Minister directed officials in her department to work in anticipation of a Remain vote – despite the DUP campaigning to quit the EU.

The paperwork – which was obtained by investigative news website The Detail – showed that, less than 24 hours before polls opened in the referendum, all of the draft answers to Assembly questions were based on the UK deciding to remain in the EU, and one answer even welcomed the end of “uncertainty” for agriculture.

Emails show the comments were “prepared as requested by special adviser [Andrew Crawford] on the basis that UK remains in EU”. The initial position of the DUP is best understood as a willingness to back a cause they thought was lost.

Since then, there has been an element of contradiction about the DUP position on the EU. Its senior MPs have been clear that Brexit should involve leaving the EU’s single market – the regulatory alignment which means that goods, in particular, can move easily across borders. They say it should also not mean a customs union, which would mean no tariffs or customs checks on goods crossing between the UK and EU.

That, however, is hard to square with the party’s “one red line” that Brexit should not erect any new barriers between Northern Ireland and the rest of the UK while also keeping the Irish border free of infrastructure. It is keeping Northern Irish regulation aligned to that of Ireland – in other words, the single market and customs union – that allows the frontier to have no checkpoints.

"No Border" placards on a bridge in Omagh, Northern Ireland

But the party has been more willing to compromise than is usually recognised, even if that is shrouded in defiant language which requires interpretation. Unlike the thoroughbred Brexiteers of the European Research Group on the right of the Tory party, the DUP has since the referendum been open to major compromise – just not the sort of compromise offered by the UK government.

In fact, that choice of one red line was a measure of the party’s openness to compromise around areas which were non-negotiable for other Brexiteers.

The DUP was probably coy in being publicly explicit about the logic of its position – that it could accept any form of Brexit, hard or soft, which treated Northern Ireland the same as the rest of the UK – because of its alliance with the European Research Group of Conservative MPs, who do not share that view.

It was the DUP’s opposition to the EU’s preferred Northern Ireland-only backstop – an insurance policy to ensure that the Irish border remained unaffected by Brexit, regardless of how the UK-EU relationship ultimately developed – which persuaded Theresa May to move towards a largely UK-wide backstop.

Theresa May greets Arlene Foster ahead of agreeing a deal to prop up the Conservatives' minority government

Now faced with Johnson’s deal, some observers now look back at that plan as one that would have been far better for the DUP, treating the UK as much more of a single entity. However, there was one fundamental difficulty for the DUP. The May backstop still treated Northern Ireland differently, necessitating some additional Irish Sea checks and tying Northern Ireland more closely to the EU.

If the DUP had been a party that had opposed Brexit, it could have argued that it had taken a potential constitutional disaster for unionism and mitigated it to a few limited areas. The DUP’s difficulty was that it had argued for Brexit on the basis that it would make things better – both constitutionally and economically. To sign up to a deal that, seen through the unforgiving constitutional prism of Northern Irish politics, had weakened Northern Ireland’s links to Great Britain and strengthened its links to the Republic of Ireland would have been a serious difficulty.

The DUP’s links to the right of the Conservative Party are more than the marriage of convenience which they have sometimes been portrayed to be. The DUP has few friends in Parliament but has more allies on the Tory right than elsewhere, with individual DUP MPs sharing with them views on everything from gay rights to abortion and, in some cases, opposition to the 1998 Belfast (Good Friday) Agreement.

While the DUP likes to present itself as unflinchingly resolute, in reality it is a deeply pragmatic party, constantly cutting deals that involve compromise. Earlier this month, in the build-up to what would become Johnson’s deal, the party made a massive concession – although it denied that it was such – by accepting there could be a regulatory border in the Irish Sea, something which Foster had previously vowed was unacceptable as part of her “one red line”.

Foster takes the plaudits after her party conference speech in 2019

Perhaps, having seen the DUP move on regulatory divergence from Great Britain, Johnson thought that the party could be pushed into further divergence, or bought off with money. Divisions within the DUP as to how much it should concede on Irish Sea checks may also have emboldened Downing Street into thinking that the party could support his proposal.

From Westminster, where the only Ulster MPs to take their seats are the DUP ten and the independent Lady Hermon, it is easy to see the DUP and Northern Ireland unionism as synonymous. However, the most recent Northern Ireland election – May’s European election – resulted in Foster’s party taking just over half the unionist vote.

A one-way union? While the DUP is hurt by how Tory MPs have discarded it, the party is not in a position to fume with righteous indignation. Recent years have exposed how some senior DUP figures – including Foster’s right hand man while a Stormont minister, Andrew Crawford – exemplified a strain of Ulster nationalist thinking that has always been present within the DUP. His role in the “cash for ash” scandal showed that Crawford viewed London as something approaching an ATM for Northern Ireland – and he was far from alone within the DUP’s ranks. Even when told that the budget for the disastrous Renewable Heat Incentive (RHI) had been blown, and after being given allegations that the scheme was being abused, he told a colleague “I am a little confused over what the problem is” because he thought – mistakenly – that the scheme was being funded by British taxpayers rather than from Stormont’s budget. To his mind, therefore, “all that will happen is that we will get more than our fair share of the UK pot. I would have thought that this is to NIs [sic] advantage”. That element of economic nationalism which at its worst is simply a grasping attempt to extract as much money as possible from the Treasury was popular in the short term with various interest groups who benefited from the extra cash pouring into Northern Ireland. But in the long term it undermines the DUP’s pan-unionist credentials at the point where it desperately needs friends in GB. Read more Read less

The scale of the unionist sense of abandonment is that virtually all of unionism’s disparate and disputatious tribes agree with the DUP that Johnson’s deal is unacceptable, seeing it in stark constitutional terms as something that would cut Northern Ireland off from the rest of the UK and bring it closer to the Irish republic.

As the DUP has desperately attempted to denounce the deal being foisted upon Northern Ireland by the man they sustain in office, it has faced widespread ridicule for arguing that what the Prime Minister is proposing would undermine the Good Friday Agreement. The party viscerally opposed the Agreement which it now clings to, and its belated reliance on that Agreement is viewed as the political equivalent of Satan quoting Scripture when it suits him.

But that is to play the man rather than the ball. Whatever the DUP’s weakness in making the argument, Mr Johnson’s proposal contains an element that pulls at the fragile threads of Northern Ireland’s political settlement.

Part of the Johnson proposal is that the Northern Ireland Assembly in Stormont would give its assent to the proposed new Irish Sea barriers by means of a simple majority vote, rather than allowing both communal blocs – unionism and nationalism – to each have a veto. It is understandable why neither Brussels, Dublin nor London would want to entrust any significant role in approving their deal to the vagaries of Stormont’s fractious parties.

But, for more than four decades, it has been widely accepted that Northern Ireland cannot operate as a majoritarian society, essentially because the majority cannot be trusted to fairly rule over the minority. Unionism, as the majority, was the most reluctant to accept that principle, but came to agree to it decades ago and it is central to the 1998 Good Friday Agreement.

Members of the Orange Order march to celebrate the Battle of the Boyne, 1690, when the Protestant King William of Orange defeated the Catholic King James II

Simple majority rule used to help unionism. But, as demography and politics have shifted, their historic majority has been eroded. So it is not difficult to comprehend why, in those circumstances, unionists will not just feel dismayed at Johnson but also question the entire basis upon which the peace process has been built if they see that, on a rare occasion where the architecture of the Agreement would protect them against a nationalist and centrist majority, the rules have been rewritten at their expense.

The truth, which they dare not admit, is that the DUP backed Brexit with no thought of what would happen to that which it holds most precious of all: the Union.

If Johnson’s deal passes, there is an ineluctable logic to where the DUP is likely to move. In those circumstances, the DUP, the party whose Westminster leader and chief of staff sat on the board of Vote Leave, would face an awkward reality.

In that now highly plausible situation, the only way to save the Union from being undermined would be to support a second referendum in the hope of Brexit being reversed. What the DUP viewed as a land of milk and honey has turned into something which is constitutionally hellish.

The author is political editor of the Belfast News Letter and Northern Ireland Political Editor of the i newspaper