Rishi Sunak has appointed a top employment barrister to investigate formal complaints into his deputy prime minister, Dominic Raab, who has been accused by multiple civil servants of bullying behaviour across several government departments. The lawyer, Adam Tolley KC, who has experience of handling whistleblower claims, has been tasked with investigating the complaints “in confidence” and will report to the prime minister, who will then decide whether Raab should face sanction. Two formal complaints have already been lodged against Raab, which he has vowed to “thoroughly rebut and refute”, by officials at the Ministry of Justice and Foreign Office. However, it is understood that he is also facing several additional formal complaints from civil servants. The Guardian has revealed multiple allegations of bullying and intimidatory behaviour by Raab across three government departments – the MoJ, the Brexit department and the Foreign Office. Sunak has faced questions over his judgment in reappointing him as they came to light. Labour called on Sunak to immediately expand the scope of the inquiry to allow the proactive and independent investigation of formal and informal complaints about Raab’s alleged behaviour. Angela Rayner, the party’s deputy leader, said the government’s “troubling track record of brushing bullying behaviour under the carpet” cast doubt on the credibility of the investigation into the deputy prime minister’s conduct. Downing Street said Tolley would not be limited in his scope, meaning that he would be able to widen his investigation to look into other complaints if the prime minister agreed. It also suggested he would have access to all of the information, including emails and WhatsApp messages, required to carry out his inquiry. Government insiders said Tolley’s investigation would be conducted as swiftly as possible, and his report published in full “in a timely way”, suggesting it would not be sat on for up to six months like the inquiry into the Priti Patel bullying allegations. However, they stressed the prime minister remained final arbiter. One Cabinet Office source said: “It’s a bold step to appoint someone independent who has a reputation to protect. But what Sunak does with the report will be crucial. If he tries to hide it or refuse to publish it then he’ll be accused of being a hypocrite like Boris.” The senior lawyer will be backed up by staff from the Cabinet Office’s propriety and ethics team. The inquiry’s terms of reference state: “Information provided to the investigator is provided in confidence. The investigation should be completed as swiftly as possible and the investigator will proceed on this basis.” They add: “As set out in the ministerial code, the prime minister is the ultimate judge of the standards of behaviour expected of a minister and the appropriate consequences of a breach of those standards. The report of the investigation will be made public. These terms of reference may be updated at the discretion of the prime minister, in consultation with the investigator.” Tolley, a commercial and employment law specialist at Fountain Court chambers, previously represented King Charles in a number of claims against his household. In 2004 and 2005, he successfully defended the then Prince of Wales against claims by a former secretary, Elaine Day, that she was sexually discriminated against by Charles’s assistant private secretary and unfairly dismissed. Tolley represented an unidentified security service in a 2012 sexual harassment claim at an employment tribunal brought by a female agent against her boss and a government intelligence agency. The barrister also appeared at four separate employment appeal tribunals for the Ministry of Defence from 2008 to 2011, and for the Department for Environment, Food and Rural Affairs in 2013. Raab denied any wrongdoing during an appearance at Prime Minister’s Questions last week, when he stood in for Sunak, who was at the G20 summit in Bali. “I am confident I have behaved professionally throughout but immediately I heard two complaints had been made ... I asked the prime minister to set up an independent investigation, and of course I will comply with it fully.” Labour’s Rayner said: “There must be no hint of a whitewash when it comes to the slew of serious allegations the deputy prime minister now faces. The scope of this investigation must immediately be expanded to enable proactive investigation of Dominic Raab’s behaviour during his time as a minister, including so-called expressions of concern, informal complaints and the concerning testimony of his own former permanent secretary. “A temporary stopgap investigator, appointed in a panic, with an absurdly narrow remit is not a solution to dealing with the flood of allegations of ministerial misconduct now requiring investigation. Rishi Sunak pledged integrity and accountability, but his broken promise to appoint an ethics watchdog as one of his first acts as prime minister shows that he is already failing to stop the rot in Downing Street.”