The prospect of a Labour government has united Northern Ireland’s political parties and the Irish government in hope of a reset in relations with London after the convulsions of Brexit. Unionists and nationalists expect Keir Starmer to bring stability and focus to Downing Street’s approach to Northern Ireland and to mend frayed ties with Dublin. In some quarters there is appreciation for Rishi Sunak’s role in calming post-Brexit turmoil with the Windsor framework but few would mourn the end of an era of Conservative rule that upended politics on both sides of the border. “If Labour gets into power it will be good news for all the parties. The DUP [Democratic Unionist party] doesn’t trust the Conservatives any more than Sinn Féin does,” said Peter Hain, a Labour peer who served as Northern Ireland secretary under Tony Blair. “Relations with Dublin will be improved out of all recognition.” That makes Starmer and the shadow Northern Ireland secretary, Hilary Benn, sound like Santa Claus, but in fact there is widespread optimism, ranging from wary to giddy, across the political spectrum in Belfast and Dublin. Labour says it will ditch the controversial Legacy Act, which is opposed by all Northern Ireland parties and the Irish government. A proposed deal on veterinary standards with the EU would lessen the need for customs checks across the Irish Sea, an issue that has bedevilled the Stormont assembly. There is also belief there will be more fiscal support for Northern Ireland. Above all, there is confidence that Starmer, who knows the region from his work as a human rights adviser to the Policing Board, and Benn, who has engaged with party leaders, will treat Northern Ireland seriously and not as an afterthought in a Tory civil war. “We work with every government,” the DUP leader, Gavin Robinson, said earlier this week. “There are many who sometimes casually suggest that Labour is in some way pro-Irish nationalism. That is not true of this Labour party today that is standing across Great Britain on a pro-union ticket.” Robinson was referencing Labour’s hopes of dethroning the Scottish National party (SNP) in Scotland and Starmer’s assertion last year that a referendum on Irish unity was “not even on the horizon”. Additionally, the DUP is bitter about Tory betrayals that led to the Irish Sea border and it hopes – albeit privately, because it has not foresworn Brexit – that a UK rapprochement with Brussels will greatly reduce checks on that border. A Labour victory is a mixed prospect for Sinn Féin, which may become nostalgic for Conservative blunders that bolstered its case for a united Ireland. Benn has indicated he will perpetuate the ambiguity over exact conditions for a border poll, which under the Good Friday agreement is to be called if it appears likely that most people would vote for unification. “Their approach will be opaque,” said Peter Shirlow, the director of the University of Liverpool’s Institute of Irish Studies. “It’s political craft. If you have a strategic interest in Northern Ireland, why talk a border poll into existence? Designing that future only helps those who want it to happen.” A Labour government would, however, dismantle the Legacy Act, which gives immunity to soldiers involved in the Troubles, and may release more funds to Stormont at a time when Sinn Féin holds economic portfolios and the first minister post, and wishes to showcase success to voters on both sides of the border. Sinn Féin also hopes Labour will save its cherished project to redevelop Belfast’s Casement Park and give Northern Ireland a chance to host Euro 2028 championship matches. “Labour know that we are coming on day one to ask for this project to be built,” the first minister, Michelle O’Neill, told the BBC this week. The Irish government hopes to repair a relationship shredded by Brexit and the Legacy legislation, which prompted Dublin to launch an inter-state case under the European convention on human rights. A Starmer administration could be expected to restore “trust and warmth” to bilateral ties, said Bobby McDonagh, who was Ireland’s ambassador to the UK from 2009-13. It would also restore the principle of co-guarantorship between Dublin and London in relation to Northern Ireland, a partnership too long absent, said McDonagh. He added: “Starmer can be expected, both in tone and substance, to seek a closer relationship with the EU which, by definition, would mean a closer relationship with Ireland.” A legislator with Fianna Fáil, part of Ireland’s ruling coalition, said Ireland viewed the election as deliverance. “July 4 will be our independence day from stupidity,” he told Politico. “It’ll be gobshites out and adults in, finally. Finally!”