Rishi Sunak has insisted he will stand by Dominic Raab after he was accused of bullying staff.
The Prime Minister launched a defence of his deputy as he rejected calls for him to face investigation or the sack.
Civil servants have complained about Mr Raab’s behaviour towards them with warnings he has created a “climate of fear” in his office.
The Mirror last week revealed the deputy PM has been nicknamed “The Incinerator” as he “burns through” staff so quickly.
Mr Raab is expected to stand in for Mr Sunak at Prime Minister’s Questions on Wednesday - during Anti-Bullying Week.
Antonia Romeo, the top mandarin in the Ministry of Justice, gave Mr Raab a dressing down over his treatment of staff when he returned to the department last month.
The claims against Mr Raab have raised fresh questions about Mr Sunak’s judgement just days after Gavin Williamson quit the Cabinet last week following allegations he had bullied staff.
But the PM, who has just arrived in Indonesia for the G20 summit of world leaders, said his deputy continues to have his backing.
Asked if he will launch an investigation into the bullying claims, the PM said: "I don't recognise that characterisation of Dominic and I'm not aware of any formal complaints about him.
“Of course there are established procedures for civil servants if they want to bring to light any issues. I'm not aware of any formal complaint about Dominic."
It was revealed yesterday that 40% of officials working in Mr Raab’s office when he was Foreign Secretary had said they had experienced bullying in a workplace survey.
But Mr Sunak said: "My understanding is that these surveys are annual and relate to the overall work environment, not to individuals."
Mr Raab was ousted from the Justice department when Liz Truss became PM in September but returned as Justice Secretary just seven weeks later when Rishi Sunak entered No10.
Downing Street said the Prime Minister stood by Mr Raab, with a spokeswoman adding of bullying claims: “He does not recognise this characterisation and he is not aware of any formal complaints being raised.”
The spokeswoman said “people in public life should treat others with consideration and respect” but that any allegations should follow “due process and a fair hearing”.
Yet she refused to deny knowing a “formal expression of concern” had been raised about Mr Raab - instead replying: “We are not aware of any formal complaints having been raised.”
A Government source last week told the Mirror: "He is known as The Incinerator as he burns through officials. The mood is grim in his office. People are desperate to escape the climate of fear as quickly as they can.”
Around half of the staff working in Mr Raab's private office are understood to have asked to move when it was announced he was returning.
In his first speech as Prime Minister, Mr Sunak pledged: “This government will have integrity, professionalism and accountability at every level.”
The PM’s press secretary insisted he has “zero tolerance” for bullying after Mr Williamson was forced to resign.
