The world’s poorest “will pay the greatest price” of plans to merge the Department for International Development (Dfid) with the Foreign Office, MPs have said.
Announcing the plans, Boris Johnson said the “long overdue reform” would ensure “maximum value” for taxpayers.
But the Commons International Development Committee called the move “impulsive”.
Its report also said the decision could reduce the UK’s international standing.
It also criticised the lack of consultation with the development sector before the decision was taken. Former prime ministers David Cameron, Gordon Brown and Tony Blair have also criticised the move.
The timing of the merger, in the middle of the global coronavirus crisis, was “perplexing”, the report said. “Now is not the time for a major government restructure,” it added.
It recommends the retention of a minister responsible for development, as well as a specific related Commons committee.
The government’s current plans do not include retaining Dfid’s current secretary of state, Anne-Marie Trevelyan, in her post.
However, Mr Johnson has pledged that the department’s budget will be protected and will still be ring-fenced for aid projects.
Chair Sarah Champion, a Labour MP, said Dfid “is something we should all be proud of”, adding that it was “deeply disappointing that the government failed to recognise” the department’s strengths.
“Now we are on the brink of this expertise being lost and our international reputation being damaged beyond repair.
“The fact that there was no consultation, seemingly no evidence as to why this is a good idea, really lets down the communities that UK aid is there to support,” she said.
A government spokesman said: “The new Foreign, Commonwealth and Development Office will place our world-class development programmes at the heart of our foreign policy.
“Combining the development expertise of Dfid with the diplomatic reach of the Foreign Office will maximise the impact of our aid budget in helping the very poorest, while making sure we get the very best value for UK taxpayers’ money in a world-leading department.”