The government department responsible for overseas aid is to be merged with the Foreign Office (FCO), the PM has announced.
Boris Johnson told MPs combining the Department for International Development (DfID) and the FCO would “unite our aid with our diplomacy”.
He said the “long overdue reform” would ensure “maximum value” for taxpayers.
But Labour leader Sir Keir Starmer said the merger would “diminish Britain’s place in the world”.
Former Conservative PM David Cameron also criticised the move, warning it would mean “less voice for development at the top table and ultimately less respect for the UK overseas”.
It is understood ministers are aiming to set up the new joint department – known as the Foreign, Commonwealth and Development Office – by September.
The move to combine the two, which have a previous history of being merged and split up again, has long been mooted in Conservative circles.
Announcing the plan in the Commons, Mr Johnson said the UK’s aid and foreign policies were “designed to achieve the same goal”.
He added it would allow a “single decision maker” to take a “comprehensive overview” about how overseas spending is allocated.
For too long, he said, UK aid spending had “been treated as some giant cashpoint in the sky that arrives without any reference to UK interests”.
Keeping development spending part of a separate government department, he said, “undermines the coherence of our foreign policy”.
The prime minister reaffirmed the UK’s commitment to spend 0.7% of its economic output on overseas aid.
Boris Johnson has wanted to merge the Foreign Office and Department for International Development for years.
He believes that it is wrong to have two arms of UK foreign policy acting independently, and wants more coherence so the UK can speak with one voice on overseas matters.
The UK will remain committed to spending 0.7% of its national income on overseas assistance, currently about £15bn.
But critics within the aid sector fear this merger may see more of the money focused on UK national interests and less on poverty reduction. As such, this is a politically controversial move.
Some will see it as a sensible reordering of Whitehall, to ensure joined up policy and more effective aid spending, helping the most vulnerable while also promoting Britain abroad.
Others will see it as a bureaucratic distraction that will potentially weaken the UK’s global reputation as an aid superpower.
In response, Sir Keir said there was “no rationale” for the merger, which he said was being made now to “deflect attention” from the government’s handling of the Covid-19 crisis.
He said DfID had proved one of the UK’s “best performing departments,” and abolishing it represented “the tactics of pure distraction”.
Tory MP Andrew Mitchell, who was in charge of DfID between 2010 and 2012, said abolishing the department would be a “quite extraordinary mistake”.
He said it could lead to senior development figures leaving the UK government for jobs elsewhere, “at a stroke destroying a key aspect of Global Britain”.
Oxfam, which has delivered development projects using money from DfID, said the merger would harm the fight to reduce global poverty.
The charity’s chief executive Danny Sriskandarajah said the move was “scarcely believable” at a time when the world was focused on fighting coronavirus.
“This decision puts politics above the needs of the poorest people and will mean more people around the world will die unnecessarily from hunger and disease.”
“The Foreign Office may be excellent at diplomacy, but it has a patchy record of aid delivery and is not as transparent as DFID.”
History of mergers
The department now known as DfID began life under Harold Wilson’s Labour government in 1964 as the Ministry of Overseas Development (ODM).
It was later merged with the Foreign Office under Ted Heath’s Conservative government in 1970, but was re-established as a separate ministry by Mr Wilson after his return to Downing Street in 1974.
It was re-merged with the Foreign Office again however after the election of Conservative Prime Minister Margaret Thatcher in 1979.
The current department was again carved out of the Foreign Office in 1997 under Labour after the election victory of Tony Blair, with the new name Department for International Development.