Cutting the UK's overseas development assistance budget by billions of pounds is a "bitter blow" the and deeply lamentable decision that will have a devastating impact on the world's poorest people, a group of church leaders have warned.

They accused the governing Labour Party of the UK Government of breaking a manifesto promise and urged Prime Minister Sir Keir Starmer to rethink immediately, the Church of Scotland news portal reported on Feb 27.

Labour's 2024 election manifesto said it is "committed to restoring development spending at the level of 0.7 percent of gross national income (GNI) as soon as fiscal circumstances allow," although this is not expected during the current session of the UK parliament.

The Church of Scotland, Baptist, Methodist, and United Reformed Church leaders said they recognized there is a case for increasing defense spending, but it should not come at the cost of "vital" humanitarian and development programs.

They spoke out after Starmer revealed plans to increase defense spending to 2.5 percent of national income by 2027 - spending 13.4 billion more British pounds on defense every year from 2027.

Speaking in the House of Commons, the lower chamber of parliament Prime Minister Starmer said the policy could only be funded through hard choices.

"And in this case, that means we will cut our spending on development assistance, moving from 0.5% of GNI today to 0.3% in 2027, fully funding our increased investment in defense," he told lawmakers.

"I want to be clear to the House, that is not an announcement I am happy to make."

According to the House of Commons Library, reducing the aid target to 0.3 percent of GNI would mean that the aid budget in 2027 would be around 9.2 billion pounds, down from 15.4 billion pounds if the aid target was 0.5 percent - a 6.1 billion pounds reduction.

The church leaders' statement:

"We deeply lament the government's stated intention to make further cuts to the UK's international development budget.

"This would break a manifesto promise made to people in the world's poorest communities, and have a devastating impact on lives and livelihoods across the globe.

"While there is a case to be made for increasing defense spending to support Ukraine in resisting Russian aggression, that shouldn't come at the cost of vital humanitarian and development programs, which play a crucial role in promoting human security around the world.

"UK aid programs protect women and girls from violence, provide cost-effective vaccines to babies and young children and support human rights defenders who work to prevent future conflict.

"Such programs will be under threat if UK aid is further slashed by 40 percent.

"Our churches have strongly encouraged and supported the UK in its commitment to international development, not only as a way of showing care to our global neighbours, but in recognition of the UK's historic and ongoing responsibilities to address the causes of global injustice, poverty, forced migration, climate change and conflict.

"It is a source of deep regret to see a backing away from that responsibility.

"A massively reduced UK aid budget would be experienced as a bitter blow by partners and communities in the global south, especially coming so soon after the devastating USAID cuts.

"We urge the government to rethink its decision immediately."

Emma Jackson, convener of the Public Life and Social Justice Programme Group, The Church of Scotland

Rev. Lynn Green, General Secretary, The Baptist Union of Great Britain

Rev. Helen Cameron and Carolyn Godfrey, President and Vice-President, The Methodist Church in Britain

Tim Dunwoody, team leader for Irish Methodist World Development & Relief, The Methodist Church in Ireland

Rev. Philip Brooks, Deputy General Secretary (Mission), The United Reformed Church

In 2021, the churches accused the then UK Government of presiding over a "moral failure" after it cut the budget from 0.7 percent of national income to 0.5 percent.