The DUP is under the cosh over the EU-UK government deal designed to bring some clarity to how the Irish Sea border will work a proposal anathema to most unionists.
UK cabinet minister Michael Gove spent time in the House of Commons on Wednesday seeking to reassure unionists that the new east-west border created as a result of Brexit was not a threat to the union of Britain and Northern Ireland.
A precis of the general unionist reaction was in line with what DUP MP Sammy Wilson said on Tuesday in Westminster: I am 100 per cent British and I want to remain 100 per cent British, and the reason why I have taken a stance against the withdrawal agreement … is because it diminishes my Britishness.
It wasnt surprising that the response to Wilson and the DUP the only one of the Norths five main parties to campaign for Brexit was of the I told you so variety, or as former leader Ian Paisley snr was wont to say when in biblical mode, you reap what you sow.
DUP MPs such as Wilson and Ian Paisley jnr are genuine in their ideological wish to see a strong Brexit. But there was a real sense before and after the EU exit referendum in 2016 that many or possibly most others at senior DUP level were acting expediently in taking a Leave position.
The argument ran that the DUP could adopt a John Bull hard pro-union Brexit stance safe in the expectation that the Remain side would win. That would strengthen its electoral position, particularly as its rival Ulster Unionist Party was for Remain (although quite a few Ulster Unionists voted to quit the EU).
That didnt work out.
Another reason for the unionist constitutional anxiety and anger at the DUP was that it had placed trust in UK prime minister Boris Johnson that he would be a better bet than his predecessor Theresa May in safeguarding the union.
The DUP had struck a £1.5 billion confidence-and-supply agreement to keep Mays government in power. But it jettisoned her in favour of Johnson because of opposition to Mays Brexit backstop, which would have involved some checks on goods coming into Northern Ireland from Britain.
Junk the backstop, Johnson declared at the DUP annual conference in November 2018, to the whooping delight of hundreds of delegates although it was also noted that there were some present who were wary of him.