Boris Johnson could face a shock Commons defeat over plans to cut foreign aid after dozens of his own MPs backed an amendment to reverse the cuts, in a rebellion led by the former international development secretary Andrew Mitchell. MPs tabled an amendment on Wednesday night backed by a number of senior Conservatives, including the former health secretary Jeremy Hunt, former Brexit secretary David Davis, the former Northern Ireland secretary Karen Bradley and the former immigration minister Caroline Nokes. The foreign secretary, Dominic Raab, announced last year that the UK would cut aid spending from 0.7% of national income to 0.5% – a reduction of more than £4bn. The cuts have led to funding for some programmes being reduced by 85% or more. UK aid to Yemen, one of the world’s most devastating humanitarian crises, was reduced from £197m pledged in 2020 to £87m this year and humanitarian funding for Syria halved. Funding for the Global Polio Eradication Initiative was reduced from £100m to £5m and girls’ education funding was cut by 40% on average over the previous four years. Among the 15 Conservatives who have backed the bill are the chairs of the defence and foreign affairs select committees, Tobias Ellwood and Tom Tugendhat, as well as newly elected MP Anthony Mangnall, a former Foreign Office adviser. Two other former foreign and development ministers – Sir Desmond Swayne and Harriett Baldwin – have also signed, as well as Derek Thomas, the Cornwall MP whose constituency will host the G7 summit. The Guardian understands that MPs believe they have enough support within the party to have a realistic prospect of defeating the government. The amendment, which has wide cross-party support, is backed by every former chair of the public accounts committee, including Tory MPs Davis and Sir Edward Leigh and Labour’s Dame Margaret Hodge and Meg Hillier, its current chair. The amendment, if selected by the speaker, would introduce a new clause to the advanced research and invention agency bill which has its report stage in the House of Commons on Monday. It would be a technical change to enforce the 2015 International Development (Official Development Assistance Target) Act, which obliges the government to meet the 0.7% target in 2022. Announcing the move, Mitchell said: “Every single member of the House of Commons was elected on a very clear manifesto promise to stand by this commitment. We have repeatedly urged the government to obey the law and implored ministers to reconsider breaking this commitment. “The cuts are now having a devastating impact on the ground and are leading to unnecessary loss of life. We urge the government to think again, or we shall be asking parliament to reaffirm the law as it stands so as to oblige the government to meet its legal commitment, keep its very clear pledge to British voters and uphold Britain’s promise to the rest of the world.” Ellwood urged his colleagues to get behind the move. “I’m delighted there is an opportunity for parliament get an opportunity to register its view on the utility of our soft power,” he told the Guardian. “I very much hope colleagues will support this amendment on Monday.”