Peter Robinson’s comments about a united Ireland at the MacGill Summer School in Glenties on Friday annoyed and upset different strands of unionism, although more detached observers are sure he is attempting to kickstart a necessary debate.

But as was clear on Monday, the reaction to Robinson’s remarks demonstrated that many unionists don’t want a debate because they fear it just sparks nationalist ambitions and disheartens those who work to maintain Northern Ireland as part of the United Kingdom.

Robinson’s line about a united Ireland – “I don’t expect my own house to burn down but I still insure it because it could happen” – didn’t impress DUP East Antrim MP Sammy Wilson. He countered: “Preparing for a possible united Ireland is not an insurance policy against something unpleasant happening, it is an invitation to republican arsonists to come in and burn our house down.”

The comments were “dangerous and demoralising”, said Wilson. “I don’t prepare to go to the moon in Richard Branson’s space shuttle because I have no intention of ending up there.”

Wilson’s annoyance reflected the widespread public and private political reaction from unionism. Ulster Unionist Party chairman Reg Empey accused Robinson of “becoming a Sinn Féin echo chamber” while Traditional Unionist Voice leader Jim Allister said “by his crass comments he fed the republican myth of the inevitability of Irish unity”.

Nationalist politicians unsurprisingly welcomed the comments.

Sinn Féin Assembly member Máirtín Ó Muilleoir said the remarks reflected the political reality that support for a united Ireland was growing in Northern Ireland, and that people must prepare for it, notwithstanding that Robinson obviously opposed such constitutional change.

You have to wake up to the demographic changes, you have to wake up to what can be the destabilising impact of Brexit

SDLP deputy leader Nichola Mallon said it “has always been the job of unionist leaders to make the case for remaining in the union, just as it is mine and my colleagues’ job to build the case for a new and agreed Ireland”.

Shrewd politician

Prof Peter Shirlow, a historian from a unionist background, believed that what Robinson was doing was trying to encourage unionists to make that very case for the union. He counselled that Robinson is a shrewd politician and that there were good reasons why his advice should be heeded.

“I think [for unionists] that what Robinson in some ways is getting at is that you have to wake up to the demographic changes, you have to wake up to what can be the destabilising impact of Brexit, and you need to make a case for the union,” said Shirlow, who is head of the Institute of Irish Studies at Liverpool University.

That nationalist surge was prompted by what many felt was unionist disrespect of nationalism

Unionists, as reflected in their reaction to the Glenties speech, feared that it would embolden nationalists to press more vigorously for a Border poll on a united Ireland.

Under the Belfast Agreement, Northern Secretary Karen Bradley can only call a poll if there are indications it would be carried. From recent polling and the last Westminster election there are no such indications, said Shirlow.

In last year’s spring Assembly election, Sinn Féin came within 1,168 votes and one seat short of the DUP’s 28 seats.

That nationalist surge was prompted by what many felt was unionist disrespect of nationalism, particularly through DUP leader Arlene Foster’s “crocodiles” remarks about Sinn Féin and its demands for an Irish language Act.

The election result both alarmed and galvanised unionism so that in the summer Westminster election of 2017, the DUP returned to a more normal pattern of being more than 53,000 votes ahead of Sinn Féin.

That was in line with the 2011 census figures which showed 48 per cent (864,000) of Northern Ireland’s 1.8 million population originated from Protestant households, while those from Catholic households accounted for 45 per cent (810,000) – a Protestant background majority of 54,000.

But with far more Catholics than Protestants in primary, secondary and third-level education in the North, the demographic trend is pointing towards an eventual Catholic majority which could happen in a generation or even over a shorter timeframe.

If being in the union is better than being in a united Ireland then what is that argument?

Robinson in his latter years as first minister and DUP leader was, according to Shirlow, very conscious of this shift and accordingly was attempting to effect a reconciliation with nationalism that would have the benefit of strengthening the union.

Class issue

Shirlow said what Robinson understands, but many unionists don’t, is that in terms of the future of the union the most important group in Northern Ireland are middle-class Catholics. That is the group who may be persuaded for material reasons, such as economics and the British national health service, to stick with the union rather than opt for a united Ireland in a Border poll. But insulting Catholics or disparaging a language and culture will only serve to push such people into the united Ireland camp.

A drawn-out conflict, and coping with its afternath: British soldiers on patrol in Northern Ireland in 1969. Photograph: Peter Kemp/AP Photo

Shirlow sees Robinson’s comments as a sort of “wake-up call” for unionism: “Irrespective of what you think of Robinson this is a shrewd person and I think he understands demography, and I think he understands diversity in Northern Ireland society, and I think he understands that Northern Ireland can be saved, that it can continue for some time. But I think what he is critically saying is a traditional type unionism will not save the union.”

He added: “What Robinson is saying, and this was the analogy of the insurance, you need to start making this place work. Because if Northern Ireland remains a dysfunctional place where rights are denied, in which unionism does not have a capacity to make the case for itself, then of course you are going to bring a united Ireland much closer.

“I think it is good to open that debate. If being in the union is better than being in a united Ireland then what is that argument? I think the reaction to Peter Robinson proves that there is not a proper, coherent argument. Is there anybody within unionism who is able to articulate a rational, inclusive idea of the union? That is the critical issue.”

Former Northern Ireland first minister and DUP leader Peter Robinson: Highly conscious of demographic shift, and trying to get unionists to face up to difficult issues. File photograph: Niall Carson/PA Wire

Historian, commentator and former SDLP councillor Brian Feeney also believed that Robinson was stimulating debate while taking a different perspective to Shirlow’s. Due to the concerns triggered by Brexit and the nationalist antipathy to the “crocodile” and other DUP comments about nationalists, he did not accept that middle-class Catholics in any significant numbers would support maintaining the union in a Border poll.

“The chances of nationalists supporting the union are remote with somebody like Arlene Foster or Nigel Dodds offending them on a monthly basis,” he said.

Rather Feeney detected a change in the mood of some middle-class unionists who, fearful of the fallout from Brexit, were now looking at how well the economy in the Republic is performing and how social attitudes are changing.

A Border poll now would result in the status quo, but post-Brexit attitudes could change, said Feeney.

He added that Robinson was highly conscious of the demographic shift and was trying to get unionists to face up to difficult issues.

“What Robinson is saying to unionists is that we need to discuss all this. We need to talk about it, we need to be involved in negotiations,” said Feeney.