Will the Windsor Framework prove the undoing of Jeffrey Donaldson and the DUP? The mood music amongst some of the louder elements of this fractious political tribe points to trouble ahead.

The premature champagne corks released in London and Brussels earlier this week were greeted with stony silence in the unionist heartlands. The party’s public position – and that of its leader – is that it is still chewing through the document. Though Donaldson did not issue an outright no, he did say some issues remained with what had been agreed by the UK and EU.

However, the pressure on Donaldson to respond in the negative has been cranked up by an intervention from some of the DUP’s more outspoken and mischievous types. Ian Paisley – who was first out the blocks in saying the deal ‘didn’t cut the mustard’ – has gone further, lending his name to the foreword of an analysis of the deal by the Centre for Union Studies which recommends that unionism rejects it.

This is a profound political headache for Jeffrey Donaldson

The analysis – which was conducted by John Larkin KC, the former Attorney General for Northern Ireland – has concluded that the Windsor Framework is not compatible with the Act of Union, specifically, the article which guarantees ‘unfettered trade on the same footing between and within all parts of the UK’.

A similar criticism of the Framework’s impact on intra-UK trade was also issued by Donaldson’s predecessor as DUP leader at Westminster, Nigel Dodds. All this adds to criticism of the actualities of the so-called Stormont Brake by Sammy Wilson, with the East Antrim MP describing it as effectively meaningless.

Plenty will rush to view this as the big beasts of unionism defaulting to the ‘no surrender’ stance they seem conditioned to take or politicians fond of a solo run deciding to take a stroll. However, all of this is a profound political headache for Donaldson which constricts his ability to move. The Centre for Union Studies is led by Jamie Bryson, a somewhat controversial figure in Northern Irish politics who has been at the forefront of anti-Protocol activism in recent years. He has shared a platform with Donaldson denouncing the Protocol, and for all the criticism sent his way – much of it of the sneering and condescending variety – he is a figure of influence. For him to say he cannot back the deal boxes Donaldson into a corner. Many in unionism and loyalism will take their heed from this series of interventions over the past 48 hours and follow accordingly.

Reports also suggest that within the DUP, a schism is emerging between those Assembly members who want to take the deal and those at Westminster with relatively safe sinecures who are happy to protest it. Given the travails of devolution in Northern Ireland since 2016, the party’s centre of influence has shifted to London, but some feel the quality of representation there has not improved.

This has seen some talented MLAs such as Simon Hamilton, the former economy minister, leave in recent years to return to the private sector. Failure to balance both sides could lead not only to a civil war but also a brain drain the DUP can ill-afford.

One rare positive for Donaldson has been the thoughts of Peter Robinson, the former DUP leader and the man who was the real force behind its modern surge. Not only has he urged senior DUP figures to effectively keep their mouths shut while reviewing the deal, Robinson has also told unionists to consider what will happen next should they reject it: ‘Serious thought must be give as to whether a better deal could be attained in the future if we do not react positively to this one,’ he said. Given Westminster’s short attention span, despite all its rhetorical unionism, his words are worth keeping in mind.

Ultimately, it all comes down to Donaldson. He knows the price of being an isolated unionist leader given the outsized role he played in the vanguard movement against David Trimble while he laboured to sell the imperfect Belfast Agreement to the unionist people. Will he be as bloody minded as Trimble and press ahead with the deal, knowing it could blow up his own career and his party?