The leaders of Scotland, Wales and Northern Ireland have declared that the future of their nations “belongs in the European Union” as they reaffirm their commitment to independence from the United Kingdom.

Plaid Cymru, the Scottish National Party (SNP) and Sinn Féin have signed a new memorandum of understanding pledging closer cooperation and declaring that Scotland, Wales and Northern Ireland have the right to determine their own constitutional futures.

The agreement says the three nations have distinct histories, identities and political traditions, while asserting that each has the right to determine its future through democratic means and in accordance with the wishes of its people.

The parties say they will work together in areas including economic development, energy, European relations and international cooperation.

They argue that their nations need “greater ambition, greater economic opportunity and a stronger voice” in determining their futures.

The memorandum marks a significant statement of cooperation between the three pro-independence movements at a time of growing debate over the UK’s constitutional future.

“For the first time ever,” the agreement states, people across the islands have First Ministers in Scotland, Wales and Northern Ireland who are committed to independence from the United Kingdom.

The parties say this represents a clear indication that “Westminster’s time is coming to an end”.

They argue for a new political model based on nations working together as equals, sharing expertise and developing relationships based on mutual respect and common interests.

Economic and energy cooperation

The three parties have pledged to explore practical areas in which closer cooperation could deliver economic benefits.

They say they want to develop “productive, prosperous economies” capable of creating jobs, tackling inequality and distributing wealth and opportunity more fairly.

The parties also reject what they describe as “Whitehall’s broken economic model”, saying their alternative would prioritise social justice and reducing inequality.

Energy is another key area of cooperation.

The agreement calls for greater development of the nations’ own energy resources, particularly renewable energy, with the aim of reducing energy costs for households and businesses.

“The energy wealth of our nations should serve the needs of our people,” the memorandum says.

Push for closer ties with Europe

The agreement also places renewed emphasis on relations with the European Union.

The three parties say Brexit has damaged their economies and reduced opportunities for their populations.

“Europe is our common home,” the memorandum states, adding that the future of their nations “belongs in the European Union”.

The parties say they want to rebuild and strengthen European relationships, creating greater opportunities for trade, investment, culture and cooperation.

‘Right to self-determination’

The memorandum makes a direct assertion of the right of the nations to determine their own constitutional futures.

“Our nations have the right to self-determination,” the parties state.

They argue that no Westminster government should have the power to block democratic decisions or undermine the principle that people should determine their own future.

However, the agreement also acknowledges differences between the three parties over constitutional arrangements.

“We recognise that our parties have different constitutional positions and that each nation will determine its own future in its own way and in its own time,” the memorandum says.

The declaration comes as pressure for constitutional change continues to shape political debate across the United Kingdom, with the SNP, Plaid Cymru and Sinn Féin each pursuing different political routes towards greater self-government or independence.