Rishi Sunak will appoint an “independent investigator” to examine complaints made by staff who worked for Dominic Raab, but No 10 is unable to say when the probe will start.
Work is underway to find a person with “requisite experience” – in the absence of a permanent ethics adviser, after Boris Johnson failed to fill the role, Downing Street said.
But a spokeswoman could not say the investigation will start by Christmas, saying: “I’m not going to put a date on it”.
There is also no commitment to abide by all its findings, the spokeswoman saying: “The prime minister is the ultimate arbiter of the ministerial code.”
She insisted Mr Sunak still has full confidence in his deputy prime minister – despite setting up the inquiry – and denied he is “prejudging” the probe in saying that.
Mr Raab revealed on Wednesday – after days of allegations of alleged bullying – that two separate formal complaints have been made against him, in his previous postings at the Foreign Office and the Ministry of Justice.
Requesting an independent investigation, he said: “I look forward to addressing these complaints, and continuing to serve as Deputy Prime Minister, Justice Secretary, and Lord Chancellor.”
With Mr Sunak absent at the G20 summit, he immediately had to face Labour’s deputy leader Angela Rayner, who called on the government to “drain the swamp”.
She taunted Mr Raab by saying he “has had to demand an investigation into himself, because the prime minister is too weak to get a grip”.
“The deputy prime minister knows his behaviour is unacceptable, so what is he still doing here?” Ms Rayner demanded to know.
The former head of the diplomatic service, Simon McDonald, revealed that some Foreign Office staff working for Mr Raab were “scared to go into his office” because of his “controlling” behaviour.
Ministry of Justice officials have reportedly ruled there must be a senior civil servant in the room at all meetings involving the deputy prime minister.
But, in the Commons, Mr Raab condemned Labour’s attacks as “bluster and mudslinging” and insisted he believed he had done nothing wrong.
“I’m confident I behaved professionally throughout but of course I will engage thoroughly and look forward to transparently addressing any claims that have been made,” he told MPs.
The No 10 spokeswoman defended keeping Mr Raab in post while the inquiry is conducted, saying: “The facts will be presented to the prime minister and he is not going to pre-empt that.”
She always insisted the investigator will be “independent”, despite being appointed by the prime minister with no guarantee that terms of reference will be published.
“An independent investigator will be appointed by the prime minister to establish the facts and to provide their findings to him. This will be a prime ministerial appointment, they will report into him,” the spokeswoman said.
There is no deadline for finding a permanent adviser on ministerial interests – a post vacant since Christopher Geidt quit in protest in June – but Mr Sunak wants to fill it “as quickly as possible,” she added.
