Senior colleagues of the health secretary, Steve Barclay, have insisted he is not a bully, after Whitehall sources said concerns had been raised about his alleged conduct towards civil servants. The sources said informal complaints had been made to Chris Wormald, the department’s permanent secretary, about the way the civil servants believed they and colleagues had been treated by the health secretary. The foreign secretary, James Cleverly, defended his fellow Conservative MP on Thursday, saying Barclay had given a “clear and completely unambiguous” statement in response to the allegations. However, Barclay has not issued a statement or commented publicly. Allies have said the allegations are untrue and no complaints have been made. Cleverly told Sky News: “I’ve worked with him on a number of occasions. He has made a statement making it absolutely clear that there have been no reports. “His statement is clear and completely unambiguous, and I am completely convinced that that is accurate.” The Department of Health and Social Care said it had not received any formal complaints about the behaviour of its ministers, but did not deny being alerted to concerns informally in the way sources described. The concerns over Barclay pre-date the publication of the Tolley report on the conduct of Dominic Raab, which led to his resignation as deputy prime minister and justice secretary last week after it found he had bullied civil servants. Six separate sources raised concerns about Barclay’s behaviour, which one said had in part also resulted in “a lot of unhappy people at the Department of Health just now”. Another said officials in the health secretary’s private office had “borne the brunt” of his behaviour. “Everyone finds him quite challenging,” said a third source. Two other Whitehall sources alleged that he had regularly “blasted” staff in front of others in the office. One of these insiders said Barclay was “constantly angry”, which was “very difficult” for officials, who now “don’t want to have meetings with him”. Another source claimed there were occasions were he “deliberately ignored” staff who tried to talk to him. A separate source added: “Barclay’s style is very macho … He would say that he’s forensic. But in reality he’s a micro-manager. He hauls people over the coals and is generally a bit unpleasant.” Senior civil servants have shared concerns that officials may be deterred from putting in complaints about poor behaviour as a result of Raab’s angry tirade against “activist” civil servants when he was forced to resign last week. The five-month investigation by Adam Tolley KC into eight formal complaints about Raab’s conduct found he had behaved in a way that “undermines or humiliates” while he was foreign secretary, and that he had criticised the work of civil service staff as “woeful” and “utterly useless” while justice secretary. Raab claimed the report established a “dangerous precedent” by setting a low threshold for bullying. The former head of the UK civil service, Bob Kerslake, has called on Rishi Sunak to speak out against the “torrent of invective against the civil service” unleashed by Raab or risk a toxic environment in Whitehall.