They are responding to widespread fears that the £13 billion budget will be cut and claims that much of it is being diverted away from fighting poverty towards more commercial and political projects.
The letter has also been signed by Rev Paul Butler, Bishop of Durham, Harun Khan, secretary general of the Muslim Council of Britain, Rabbi Danny Rich, chief executive of Liberal Judaism, and Lynn Green, general secretary of the Baptists Union.
“We, representatives of different faith communities in the UK, have come together ahead of the Comprehensive Spending Review to urge you to maintain the aid budget and protect the quality of UK aid,” the letter states.
It warns that the UK has a “moral responsibility” to continue to provide 0.7 per cent of GDP in aid, and to push for other countries to do the same.
“We also are extremely concerned to ensure that UK aid’s primary focus remains poverty alleviation, and that we deliver the highest quality aid programmes for the world’s most vulnerable people,” it says.
“We add our voices to many in asking for reassurances that the UK government will prioritise providing aid to the least developed countries, ensuring the proportion of UK aid they receive is protected from further decline.
“The UK public, and our faith communities, hope that the government will spend public money well. UK aid programmes should prioritise vital social sectors, such as health and education; promote gender equality; protect the environment; and support local solutions to build local capacity and increase sustainability.”
Rev Nigel Uden, Moderator of the General Assembly of the United Reformed Church, and Rev Michaela Youngson, president of the Methodist Conference, are among the other leaders who have signed the letter.
Among the other Scots signatories are Rev Canon David Richards, Rector of St George’s and St Paul’s Church in Edinburgh and the Muslim Council of Scotland.
UK charities have recently raised concerns that some of the UK’s aid budget is being diverted from the poorest countries to promote commercial and political interests.
The UK government has a legal commitment to spend 0.7 per cent of GDP on aid, but the concerns focus on claims that politically driven projects have been classed as aid, while strings have also been attached, such as cooperating with British industry. The UK’s aid watchdog, the Independent Commission for Aid Impact, warned that the £1.3bn Prosperity Fund, intended to reduce global poverty, could become focused on trade with wealthier economies such as China and Brazil.
Projects supported have included development of the film industry and improving museum infrastructure in China.
Meanwhile, the cross-departmental Conflict, Stability and Security Fund was used to build a £700,000 jail wing in Nigeria, allowing foreign criminals to be deported and freeing up places in British jails.
Both the size of the aid budget and the Department for International Development (DfID) have faced recent threats. Figures including Boris Johnson, a frontrunner to replace Theresa May as Tory leader, have suggested DfID should be folded into the Foreign Office. Penny Mordaunt, the international development secretary, has questioned Britain’s pledge of spending 0.7 per cent of GDP on aid.