All three Whitehall mandarins who worked with Dominic Raab while he was holding cabinet positions have now been interviewed by the official inquiry into his alleged bullying, the Guardian has learned. Sources confirmed reports that the former Foreign Office permanent secretary Simon McDonald had given evidence after he admitted last year that the deputy prime minister could plausibly be characterised as a bully. The Guardian understands that Antonia Romeo, the permanent secretary at the Ministry of Justice, and Philip Rycroft, who ran the Brexit department while Raab was in charge there, have both now also been witnesses in the investigation led by Adam Tolley KC. Their testimony was believed to have focused on what warnings they gave to Raab at the time about his alleged behaviour. All three are understood to have spoken to the cabinet minister about how he treated civil servants. Lord McDonald is understood to have spoken to Raab on several occasions during his tenure at the Foreign Office about his behaviour towards staff in his private office and during meetings. He then informally reported his concerns to the Cabinet Office’s propriety and ethics team. Romeo, the MoJ permanent secretary, is said to have spoken to Raab when he was reappointed to the department by Rishi Sunak, after being sacked by Liz Truss, to warn him that he must treat staff professionally and with respect amid unhappiness about his return. The Guardian has also reported that senior officials at the now disbanded Department for Exiting the European Union handed a document to the Cabinet Office about alleged bullying, while Rycroft, the top official there, shared general concerns about Raab’s behaviour with the then cabinet secretary, Mark Sedwill. Government insiders believe that Raab is now fighting for his political survival, with one describing him as “toast” after the Guardian revealed he faces dozens of bullying allegations from across the three government departments. Raab, who has stayed in post while the inquiry is ongoing, has vowed to “thoroughly rebut and refute” the formal complaints. He has said he is confident he “acted professionally” throughout his time in three different cabinet posts. The complaints involve his dealings with civil servants, including some in senior roles, that he allegedly “belittled and demeaned” and was “very rude and aggressive” to each day. Officials close to the inquiry are said to have been shocked by some of the claims that have emerged, including individuals being physically sick before meetings, regularly in tears and, in at least one case, left feeling suicidal as a result of the alleged behaviour. Tory MPs are privately concerned that Rishi Sunak’s handling of the row, in the wake of the Nadhim Zahawi tax affair, could undermine his pledge to instil “integrity, professionalism and accountability at every level” of his government as he tries to move the party on from the Boris Johnson era. Former cabinet minister Jacob Rees-Mogg said on Tuesday that “we mustn’t be too snowflakey” about the allegations levelled against the justice secretary. He added: “People need to be able to say this job has not been done well enough and needs to be done better. “It’s a very difficult line to judge. It is not a straightforward issue in most cases. It is how did someone react, what did somebody say, is it reasonable to demand from senior and well-paid professionals a level of good service? And then you have to judge whether that line has been overstepped. But I do worry that we are getting a bit snowflakey about this.” Dave Penman, the general secretary of the FDA union, which represents senior civil servants, said: “Even by Rees-Mogg’s standards this is outrageous. A former leader of the house, trivialising [alleged] bullying … Not only should he be ashamed of himself, but his leader and party should distance themselves from this.”