'Duplicitous' Donaldson sent Jamie Bryson to Dublin to represent DUP views - seemingly without the party's knowledge

Donaldson also gave his express authorisation for a back channel the loyalist activist had with Downing Street, where positions endorsed by party hardliners were promoted.

Mr Bryson says the former leader, now in jail for child sex crimes, made a “fatal miscalculation” in his dealings with him – and it was part of a plot involving DUP figures to “blow up” the deal.

The relationship between the now disgraced leader and Mr Bryson broke down spectacularly over Donaldson’s attempts to return to Stormont without the removal of the Irish Sea border – one of the party’s seven tests for such a return.

The souring of relations between the men culminated in an unknown DUP member wearing a wire to a crunch party executive, allowing Mr Bryson to post information from the private meeting on social media in a hugely embarrassing episode for Donaldson.

When claims about a meeting between Mr Bryson, EU diplomats and the Irish government were broadcast by the BBC’s Nolan Show in 2023, the party denied it. One senior source laughed off the idea that “that man” would be sent to represent the DUP.

Now, the DUP says Jeffrey Donaldson “led a double and duplicitous life” – and its political positions were taken through party structures rather than any individual.

The Dublin meeting took place in advance of the announcement of the EU-UK Windsor Framework accord – an attempt to soften the worst impacts of the Irish Sea border. It did not, as the DUP wanted, remove it.

At the time, TUV leader Jim Allister, Mr Bryson and some senior DUP figures were pointing out that the frontier could not be removed without getting rid of the application of EU law in the province. However, that was not part of the DUP’s seven tests – and many in the party establishment were bought into the idea that Northern Ireland could have the so-called ‘best of both worlds’, while also reducing Irish Sea border checks.

At this time, Donaldson was telling Mr Bryson that he would be raising the removal of EU law with the government.

The News Letter also understands Jamie Bryson was writing policy positions which were then privately endorsed by the DUP leader, and delivered to Downing Street via an intermediary.

The purpose of this was unclear. The party had its own seasoned negotiators and regular meetings with people at the top of government.

One theory, promoted by sources close to the Irish government, is that there was an attempt to keep Mr Bryson distracted while a deal was being hammered out – due to his influence within the DUP and unionism more broadly.

Another is that Donaldson was trying to ride two horses – and pacify his internal critics. Positions which Mr Bryson was involved in drafting, sometimes on behalf of the Centre for the Union think tank, were delivered to Downing Street via the intermediaries with Donaldson’s endorsement. The DUP leader also took part in a meeting involving the intermediaries and Jamie Bryson.

Former DUP MP Ian Paisley was part of that think tank. He publicly said he wanted significant changes to the framework – comments the DUP distanced itself from.

The intermediaries claimed to be passing Mr Bryson’s concerns about the Windsor Framework to Downing Street, with questions being passed back for Mr Bryson to answer. The proposals centred around a form of mutual enforcement.

Mr Bryson said: “Jeffrey Donaldson had me go to Dublin during Windsor Framework negotiations to set out a position on Protocol to 7 EU ambassadors, and others. He expressly told the facilitators this was the DUP position and I had his ‘full authority’ to set out the position. Self evidently the position was a hardline one.

“He also authorised a paper going to Downing Street in same terms. A very senior figure in NI, who was going direct to No 10, explicitly asked Donaldson to confirm that the position set out- which was extremely hardline - was in fact the DUP position. He expressly confirmed this was so; this was witnessed by two senior diplomats.

“At the same time he then had his press office trying to leak the Dublin engagement, in totally false terms, to try damage me. This is despite Donaldson expressly sending messages in advance saying he was ‘trying to get a party colleague there’.

“I challenged him on this - and he flatly denied it. In fact, he expressly stated I should go on Nolan Live that very night and again set out the same position, which I did. He blamed his own press office on leaking and ‘mischief making’.

“It now transpires he was doing all of this without telling his own DUP colleagues, and worse still was having them negotiate from a much weaker position”.

Mr Bryson addedr: “In my view Jeffrey thought he was playing a clever game in that he believed I could be brought along to a moderate position and he could split anti-agreement unionism and isolate Jim Allister.

“That was always a fatal miscalculation, my interest was in pulling Jeffrey into our orbit, not the other way around.

“That’s why when all this was going on he believed he might bring us along, but little did he know senior members in his own party were already onboard to blow it all up.”

A DUP spokesman said: “Following the guilty verdict it is clear that he [Donaldson] led a double and duplicitous life.

“From a political perspective and throughout the years of negotiations on the protocol and Windsor Framework, the DUP's position was determined through the party's established internal decision-making structures.

“Those structures, rather than any one individual, guided the party's approach and decisions.

“The DUP remains focused on securing the full restoration of Northern Ireland's place within the United Kingdom and addressing the ongoing challenges created by the continued application of EU law in Northern Ireland.”