Dominic Raab’s department is carrying out a major recruitment drive for private office staff, the Guardian can reveal. A hiring spree has been launched that initially sought to recruit 10 private secretary jobs in the Ministry of Justice (MoJ) – a figure Whitehall insiders and former cabinet ministers said they had never seen for a job of that nature. There is understood to only be one vacancy across the private offices, while the remainder of the successful applicants will be placed on a “merit list” so they can fill the role at short notice if needed. Separately, Raab, the justice secretary, is being investigated over eight accusations of bullying spanning his time at three departments – the MoJ, Foreign Office and Brexit department. He denies any wrongdoing and has said previously he has acted professionally throughout his political career. Downing Street has refused to put a timeframe on when the inquiry, being led by employment barrister Adam Tolley, will conclude and Rishi Sunak has continued to allow Raab to serve as his deputy prime minister. The job adverts come after the Guardian revealed a third of staff in ministerial private offices in the MoJ told an internal Whitehall survey they had been bullied or harassed while working in their current roles in the past year. The survey showed that 10 of the 33 people who worked most closely with the justice secretary said they had been a victim of bad behaviour. A job recruitment advert, seen by the Guardian, initially said the MoJ was seeking up to 10 private secretaries to work in ministers’ and the permanent secretary’s private office. Applicants were told the role would “involve a significant amount of interaction with ministers and/or the permanent secretary”. The MoJ also said staff would need “experience of building effective working relationships” and a good use of judgment. After being contacted by the Guardian, the MoJ rewrote the job advert to clarify there was only one job vacancy. However, a spokesperson said “the intention is to create a reserve list that can be called upon so that roles can be quickly filled in future”. They added: “This is a proactive recruitment campaign to ensure we can fill roles across our private offices for the deputy prime minister, junior ministers and permanent secretary, as and when vacancies arise.” Alex Thomas, of the Institute for Government (IFG), said it was “unusual to recruit this number of private secretaries at this level in one department”. He said: “It does suggest both that there is clearly a need to recruit more private secretaries into those jobs and that the demand is of a sufficient level of seniority to recruit G7s [civil service grade 7 employees] rather than more junior staff.” The IFG estimated that between five to 18 staff work in a minister’s private office. Whitehall sources claimed the apparent need for so many private secretaries was “embarrassing” for Raab. One said: “You don’t have to be a sadist to work here, but it helps.” The Liberal Democrats’ chief whip, Wendy Chamberlain, pointed out Sunak had still failed to appoint an ethics adviser, a role that has remained unoccupied since the resignation of Christopher Geidt in June. Chamberlain said: “The fact that the post of ethics adviser has now been vacant for over six months tells you everything you need to know about this government’s commitment to integrity and standards. “Sunak should finally show some backbone by suspending Raab as justice secretary until this investigation is complete. That would go some way to reassuring civil servants and the public that there isn’t one rule for Conservative ministers and another for everyone else.” Given the absence of an ethics adviser, the head of propriety and ethics in the Cabinet Office was urged by Chamberlain to open an investigation himself. However, in a letter seen by the Guardian, he told her any allegation of breaches of the ministerial code could only be handled by Lord Geidt’s successor.