Downing Street is facing growing anger from staff at the Department for International Development (DfID), some of whom accuse it of exploiting the Covid-19 pandemic by pushing through a merger with the Foreign Office (FCO). Plans had long been mooted to combine the two Whitehall departments but insiders were shocked by the timing and manner of the announcement – which came without union consultation, with many staff finding out via an apparent leak to the media. DfID employees criticised the merger, with one saying staff were “devastated, demoralised, angry, anxious” and claiming Boris Johnson had seized on the pandemic to “achieve a long-term goal” in axing the department as a standalone entity. Another said it was a politicised, opportunistic move that had “pulled the rug away” from under staffers’ feet, with many worried about job security. Unions representing DfID civil servants, who have written to the FCO demanding formal consultation over the plans, said their members were “shocked and angered” and that the staff testimony obtained by the Guardian was a “damning indictment”. Sarah Champion, the chair of the Commons’ international development select committee – which released an interim report earlier this month arguing for the retention of DfID as a standalone government department – said the timing and way in which the merger was announced was “callous”. She added that the government’s treatment of staff was “outrageous”. Johnson announced the merger on Tuesday in the Commons, pledging to maintain DfID’s £15bn budget and the UK’s commitment to spend 0.7% of GDP on aid. Many DfID employees discovered the news hours earlier from a tweet by the BBC’s political editor, Laura Kuenssberg. DfID, formed in 1997 – although incarnations have existed under previous governments – employs about 3,600 staff working in offices in London and East Kilbride, as well as around the world. Plans for the new department, to be called the Foreign, Commonwealth and Development Office and due to be set up by September, have been criticised by three former prime ministers. One DfID employee, whose identity the Guardian is protecting, said: “I feel like the majority of staff have a mix of emotions on the merger – devastated, demoralised, angry, anxious. You could just pick a negative emotion and I’ve felt it at some point since we heard the news. “It’s been a long-held goal for the Conservative party, and Boris Johnson in particular, to merge the departments, so it wasn’t a complete bolt from the blue. But nobody expected it would come so quickly. As civil servants, we felt we should have been told first, but we found out through leaks to the media before the prime minister’s statement to the House of Commons. It just shows the contempt they have for DfID. “This is about the prime minister using the pandemic to achieve a long-term goal and making a snap announcement about it and not even giving staff the opportunity to react.” Another DfID employee said: “Like most people at DfID, I’m really passionate about my job and I’m still reeling at the news of the merger. There’s been murmurings about it, the signs were there, but no one thought it would happen now as we’re in the midst of the pandemic. We’re all sitting at home struggling with dealing with the ramifications of this. It’s pulled the rug away from everyone’s feet. “There’s a tide of confusion, disbelief and uncertainty among staff. Are their jobs safe? How is this going to work? How long is it going to take? They’re saying it’ll be done by September but that’s 11 weeks away, and the government doesn’t move quick. Then there’s the question of whether this is a merger or a Foreign Office takeover. Are we being subsumed? We’re angry and upset. There have been a lot of tears. “I think the government has been opportunistic with its timing on the merger announcement. They seem to be using the crisis so that this goes under the radar. It’s a politicised move, and about cuts as well.” Mark Serwotka, the general secretary of the Public and Commercial Services Union (PCS), said: “The testimony people in DfID have given is a damning indictment of the decision to merge the department with FCO … Boris Johnson’s slash-and-burn approach to international aid not only threatens the livelihoods of our members in DfID and FCO but will significantly damage our relations with other countries at a time when we need all the friends we can muster.” Allan Sampson, the national officer at FDA – which represents senior civil servants – said: “Members in DfID were shocked and angered by the announcement, made worse by the fact they initially found out about it through the media. Their immediate fear is for the number of jobs available within the new department, but concern also exists regarding the nature of the new work.” Champion said: “DfID staff do the job because they believe in the work, it’s more than a job for them – it’s a moral drive to try and alleviate poverty. To have the government use the department as a pawn in this way and staff treated with so little respect or compassion, is outrageous. It shows a level of a callousness that I would never expect of a UK government. I’m not fundamentally against a merger, I just haven’t seen any evidence that shows it’s the right way forward.” A government spokesman said DfID staff “can take pride” in their work, saying their “ambition, vision and expertise will be at the heart of the new department”, which will “bring together our international effort and maximise the influence and impact of our world-leading development and foreign policy experts”. They added: “The merger will mean adjustments in how teams are structured in the new department, and some roles and responsibilities across both DfID and FCO will change. But there will be no compulsory redundancies, and we will work closely with staff throughout the process of implementing the merger – including through the unions.”