The charity which works with some of the world's poorest communities was responding to a speech this morning by the International Development Secretary, Penny Mordaunt.
According to a leak of her speech in The Sun newspaper, the government wants to enforce a major change to international rules so private money can be included in meeting the aid target of 0.7% of the UK's annual income.
Christine Allen, director of policy and public affairs at Christian Aid, said:
"Public development aid has a vital role to play when it comes to eradicating poverty and meeting the world's sustainable development goals (SDGs) in a way that leaves no one behind. Publicly funded support for the most vulnerable is a hallmark of a civilised society.
"Private investment is also needed but is much less likely to reach the most vulnerable communities in the poorest countries. Suggesting that private sector investments, which have to make a return for investors, could replace rather than supplement public aid and still be effective at addressing poverty is wrong."
The charity said any attempts to play politics with the aid budget will raise questions about how aid policy is being developed and in whose interests.
Premier has contacted the Department for International Development for a response.
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