Sinn Féin has become Northern Ireland’s largest party in Westminster after voters turned against the Democratic Unionist party and delivered a shock result that has been labelled the fall of the house of Paisley. The DUP lost three of its eight Westminster seats in Thursday’s election, including the North Antrim stronghold held by Ian Paisley and before that his late father since 1970. The party had braced for a bruising night but was shaken by the scale of defeats and a narrow escape in East Derry, a previously safe seat that it almost lost. Sinn Féin celebrated after retaining its seven seats, completing a hat-trick as the biggest party in local government, the Stormont assembly and now Westminster (although the party abstains from taking its seats in parliament). It came within a few hundred votes of ousting Gregory Campbell in East Derry. Conor Murphy, the party’s Stormont economy minister, laid a marker for the Labour government by saying the results showed an electoral trend in support of Irish unity. He urged all sides to engage in dialogue about the region’s constitutional future. “The idea of putting our head in the sand and not recognising the change that’s happening does a disservice to the entire community. And I would hope that more and more people from the unionist population become involved in that discussion, make sure that their voices are heard,” he told the BBC. However, the DUP losses reflected not gains for nationalism but divisions within unionism, which will send the same number of MPs to Westminster as before. Paisley lost to Jim Allister of the Traditional Unionist Voice, a small hardline rival that blamed the DUP for post-Brexit checks on goods coming from Great Britain. The margin, just 450 votes, was a psychological and symbolic blow to a party founded by Ian Paisley Sr. It used to be said that DUP majorities in North Antrim were hefty enough to be weighed rather than counted. Paisley declined to answer questions from the media and blew a kiss before leaving the count centre. He had been endorsed by Nigel Farage. Allister said: “This is a momentous outcome and is the end of an era and a dynasty. Unionism does need to regroup in the light of what has happened and the DUP needs to carry the responsibility for their losses.” He accused the DUP of attempting to “hoodwink” voters into believing the Windsor framework deal removed the Irish Sea border. The DUP’s Paul Girvan lost to the Ulster Unionist Robin Swann in South Antrim. The party also lost Lagan Valley, previously a DUP bastion that was vacated by its former leader Jeffrey Donaldson following sex offence charges, to Sorcha Eastwood of the Alliance party. Alliance’s joy was tempered by its deputy leader, Stephen Farry, losing his North Down seat to the independent unionist Alex Easton, and Naomi Long’s failure to dislodge the DUP leader, Gavin Robinson, in East Belfast. The Social Democratic and Labour party’s (SDLP) two MPs, Colum Eastwood and Claire Hanna, retained their seats. Ireland’s taoiseach, Simon Harris, congratulated Keir Starmer and said a Labour government could herald a “great reset” in UK-Irish relations frayed by Brexit. “The relationship between Ireland and the United Kingdom is deeply consequential for all people across these islands and the relationship between an Irish taoiseach and a British prime minister is vital,” he said. He alluded to Dublin’s belief that successive Conservative governments had undermined the Good Friday agreement, a legacy of Tony Blair’s premiership. “In the Labour party manifesto the language towards Ireland was language of partnership and as co-guarantors of our shared peace. This morning from Dublin I want to send a message to London that I will match Keir Starmer’s commitment and energy to our peace process and to our future potential in so many areas.” There is widespread support in Belfast and Dublin for Labour’s plan to scrap the Legacy Act that offers conditional immunity to soldiers and paramilitaries involved in the Troubles.