Dominic Raab has said if an allegation of bullying is upheld against him he will resign from Rishi Sunak's Cabinet.
The Deputy Prime Minister - a close ally of Mr Sunak - is currently facing a Whitehall sleaze probe into allegations made by dozens of officials about his behaviour.
In total there are eight formal complaints involving at least 24 civil servants against Mr Raab, who also served as Foreign Secretary under Boris Johnson.
