Prime Minister Sir Keir Starmer is to attend his first meeting of the British-Irish Council, which is being hosted in Edinburgh on Friday.
The Labour leader will hold talks with Scottish First Minister John Swinney, Irish Taoiseach Simon Harris, Welsh First Minister Eluned Morgan and Northern Irish First Minister Michelle O’Neill.
The summit – which comes 25 years after the first meeting in 1999 – is expected to focus on the climate crisis and transitioning to clean energy.
It will also be attended by some deputy leaders and senior government ministers, as well as representatives of crown dependencies.
The 42nd meeting of the council will explore how to finance a so-called “just transition” for workers, as nations aim to move from fossil fuel energy production to greener alternatives.
Sir Keir has named improving household finances and a transition to clean energy among his government’s six priorities.
He has vowed to work constructively with devolved administrations since taking office in July.
John Swinney said the meeting provided a forum on climate change “to discuss the greatest challenge facing the next 25 years”.
He added: “The need to share our knowledge, our efforts and our actions is no less urgent today than it was when the first British-Irish Council meeting was held in 1999.”
The council was created as part of the Good Friday Agreement to strengthen working relations between nations.
Yet relations between Westminster and Holyrood are being tested by a row over the UK government’s plans to increase employers’ National Insurance from April.
Holyrood ministers say Scotland, which has a proportionally larger public sector than the UK as a whole, needs more than £500m to compensate for increased public sector staffing costs.
It is understood the Treasury has proposed a payment of about £300m. SNP Finance Secretary Shona Robison said she would not “settle” for that figure.
The UK government says Holyrood is receiving more money than ever before from the Treasury in the next financial year.
There is also tension between the governments over a Scottish Budget proposal to effectively scrap the two-child benefits cap north of the border.
The UK-wide policy was originally introduced in 2017 by the Conservative government and has been kept in place by Labour.
It prevents parents from claiming universal credit or child tax credit for a third child, with a few exemptions.
Swinney said he wanted to end the “heinous” two-child limit “because the UK Labour government has to date failed to do so”.
However, he will require assistance from the Department for Work and Pensions to create a system that will allow Holyrood to provide funding to the families of 15,000 affected families in Scotland.
Sir Keir said he was committed to tackling child poverty, but said scrapping the cap was not a “silver bullet”.
