UK Labour leader Jeremy Corbyn is to call for the revival of a contentious peace process mechanism to enable the UK and Irish Governments to work together to save powersharing in Northern Ireland.
In a speech in Belfast today, Mr Corbyn will urge British prime minister Theresa May to reconvene the British Irish Intergovernmental Conference - a body that offers the Irish a consultative role in non-devolved matters concerning Northern Ireland.
Sinn Féin and the SDLP have been demanding the re-establishment of the conference, which last sat in 2007, as a means to plot a way forward amid the devolution crisis in Belfast.
However, unionists are wary of the body, and associated suggestions the Irish Government could have a significant role in deciding the next steps for the region's rudderless public services.
Democratic Unionist leader Arlene Foster has dismissed the conference as a "talking shop" and instead called for direct rule UK ministers to take decisions on Northern Ireland at Westminster until such time as a powersharing administration can be pieced back together at Stormont.
On his first visit to the region since becoming leader, Mr Corbyn will focus on the powersharing impasse in a speech at Queen's University.
The Labour leader is due to say: "Devolution and power-sharing have given every community a voice and helped maintain the peace process.
"If the current stalemate in Stormont cannot be sorted out in Belfast, I call on the UK government to reconvene the British-Irish Intergovernmental Conference.
Northern Ireland has been without a properly functioning powersharing government for more than 16 months due to a bitter stand-off between the two biggest parties, the DUP and Sinn Féin.
A row that broke out over a botched green energy scheme, and widened to encompass long-standing disputes such as the Irish language, gay marriage and Troubles legacy issues, shows no sign of resolution.
Mr Corbyn, who is spending two days in Northern Ireland, will also use his speech at Queen's to make clear that Labour will not support a Brexit deal that results in the re-imposition of a hard border on the island.
He will argue the best way to avoid border checks is through a UK-EU customs union - which would offer the UK a say on future trade deals - coupled with a "new and strong relationship" with the EU Single Market.
"Driven by the free-market fantasists within their ranks, the reckless Conservative approach to Brexit is a very real threat to jobs and living standards here in Northern Ireland and risks undermining and destabilising the co-operation and relative harmony of recent years," Mr Corbyn will say.
"That is why Labour has put forward a plan that would go a long way to solving this issue, a plan for which I believe there is a majority in Westminster. Let's not give up years of hard fought co-operation and stability for the pipe dream prize of race-to-the-bottom free trade deals with the likes of Donald Trump.
"Opposition to the idea of bringing back a hard border to this land isn't just about avoiding paperwork or tariffs, important though that is, it's about deep rooted cultural and community ties.
Mr Corbyn's visit comes amid ongoing commemorations to mark the 20th anniversary of the historic Good Friday peace agreement.
He will argue that securing economic advances for all citizens is the way to extend and deepen the peace in Northern Ireland.
"Look back at the sacrifice and courage shown at all levels of society that paved the way for something that had once seemed impossible," he will say.
"That was the spirit of the Good Friday Agreement. We all need that spirit again - Stormont and Westminster parties, the British and Irish Governments, business and unions, UK and EU negotiators - if we want to secure 20 more years of peace and greater prosperity for the many not the few."
Calling for economic justice and prosperity, he will add:
"Peace can - and must - be extended through real social and economic advances for all communities, with the state at regional and national level prepared to act to bring about a full-scale upgrade of the economy.
"While many economic decisions for Northern Ireland are rightly decided in Stormont, a Labour government in Westminster would make sure that Northern Ireland has more money to invest in its people and its public services. We will make sure the people of Northern Ireland do not miss out.
"We are committed to supporting manufacturing in Northern Ireland and Labour's recent pledge to reverse the decision to put the £1 billion contract to build the Royal Fleet Auxiliary ships out to international tender will keep jobs and prosperity in Britain's shipyards and could benefit Belfast."
Tory party chairman Brandon Lewis said: "Labour are only interested in frustrating Brexit rather than making it a success for the whole United Kingdom.
"This Government remains resolute in our commitments to Northern Ireland, including upholding the Belfast Agreement.
"Labour, on the other hand, say one thing in public but then in private say the Brexit risks to the Belfast Agreement were being played up."