The DUP's dangerous liaison with Boris Johnson began before he entered No 10. The former London mayor was welcomed to the DUP's 2018 conference in Belfast by a beaming Arlene Foster and her deputy Nigel Dodds, who told delegates the party was at the "epicentre" of British politics having agreed a confidence and supply deal to prop up Theresa May's government.
The former foreign secretary's off-the-cuff ramblings made little sense – he joked about scenarios involving Star Wars light sabres to illustrate how Britain and Northern Ireland might prosper together once free of the EU. The member for Uxbridge and South Ruislip further cemented his reputation for eccentricity by throwing his weight behind the DUP’s ‘bridge to Scotland’ plan, something we'd hear a lot more of in the subsequent months but has, as many anticipated, come to nothing.
His call for ditching the backstop in the UK-EU withdrawal deal struck a chord but like the DUP he was unable to offer a viable alternative that wouldn't involve compromise. He told the party that no British government "could or should" sign up to a post-Brexit border in the Irish Sea.
The following July he became Tory leader, succeeding Theresa May, who'd been continuously frustrated by the pro-Brexit European Research Group in her efforts to secure agreement with EU.
He vowed to 'get Brexit done' but the hardline language adopted during his campaign wasn't matched by actions.
In October 2019, following bilateral talks between Johnson and Taoiseach Leo Varadkar, the UK and EU agreed to a revised deal, which replaced the backstop with a new Northern Ireland Protocol – yet all the time the then PM insisted there would be no border in the Irish Sea.
Two months later, the Tories won their greatest parliamentary majority since the Thatcher era, meaning the DUP was surplus to requirements. The ever-duplicitous Johnson retained a pretence of resisting an Irish Sea border but it was clear to the world that he planned to throw the DUP under a bus – and duly did.
The Brexit allies' relationship was never the same again.
