The post-Brexit trading arrangements, the so-called Northern Ireland protocol agreed with the European Union, has put strains not only on the British-run province but also on ties between London and Brussels over the deal.
But over the last few months, the tone of talks to try to resolve differences over the protocol has softened, with the antagonism that marked the discussions since 2019 replaced by what appears to be a new push to find a negotiated settlement.
On Monday, the two sides reached agreement on a way forward to tackle one point of conflict.
London has to walk a fine line. Ministers want a negotiated settlement with the EU rather than triggering another legal dispute over the Brexit deal, but also must keep on board unionist politicians in the province who have led a near year-long boycott of the power-sharing government in Northern Ireland.
After securing agreement on "the way forward" on giving the EU access to customs data, British foreign minister James Cleverly and Northern Ireland minister Chris Heaton-Harris will speak to lawmakers and businesses in Belfast.
"My preference is for a negotiated solution, but the UK's priority is protecting the Belfast (Good Friday) Agreement and preserving political stability in Northern Ireland," Cleverly said in a statement, referring to a 1998 peace deal which ended three decades of violence between mostly Catholic nationalists and largely Protestant unionists, or loyalists.
"I am listening to the concerns of people and businesses in Northern Ireland and am keenly aware that the current situation isn't working. We need to address those issues with the protocol that risk and undermine the place of NI (Northern Ireland) in the UK."
The Belfast meeting is the latest in a flurry of renewed diplomacy since Prime Minister Rishi Sunak was appointed in October. Talks on solving the issues with the protocol had all but stalled under his predecessors Liz Truss and Boris Johnson.
Irish Foreign Minister Micheal Martin, who spoke to the leaders of the main Northern Irish parties by phone on Monday, is also due to meet Heaton-Harris in Belfast later this week.
The protocol was put in place to try to preserve the 1998 peace deal by avoiding a hard border between Northern Ireland and EU member Ireland, but it also meant the province all but remained in the bloc's single market for goods, requiring checks on some products arriving from the rest of the United Kingdom.
Britain has refused to implement many of the checks and has criticised the EU for being overly zealous in implementing the protocol, hurting businesses in the province and straining ties between political groups. Brussels has said it is open to being flexible on the protocol but has refused to rewrite it.
London is also keen to solve the issue to help get Northern Ireland's regional assembly up and running again - something the pro-British Democratic Unionist Party (DUP) says cannot happen until the checks have gone.
"I am firmly of the belief too that what people in Northern Ireland want most is to see their elected politicians back at work," Heaton-Harris said in the statement. "Accountable political leadership is fundamental to secure a sustainable future for all in NI."
(Reporting by Elizabeth Piper; Editing by Angus MacSwan)
