The chief executive of the National Bullying Helpline – which is at the centre of allegations of bullying at 10 Downing Street – was previously accused of bullying and intimidating staff.
Documents seen by the Daily Mirror show Christine Pratt lost a 2003 employment tribunal for sexual discrimination after being accused of bullying.
Employees of the Japanese firm Sanden testified that she was “aggressive” and “confrontational”.
Pratt was accused of making “disparaging” remarks about another worker’s command of English, which he found “extremely hurtful”.
And in one case, she “thrust her face” close to a colleague and “screamed very loudly into his ear” leaving the man shocked and in pain.
Pratt refused to speak about the case.
She told the Daily Mirror: “That’s the subject of a tribunal, which is history and it’s one of the reasons I do what I do today.
“Also, it’s not relevant to the issue we are raising with regard to the prime minister’s office.”
Pratt previously insisted to Personnel Today that she had not breached confidentiality by revealing the calls made to the hotline.
Bullying UK director Liz Carnell said Pratt should “consider her position” after her revelations.
A businessman also told how he called the charity for help in 2007 and was asked by Pratt for a £300 deposit before she passed him on to an “associate”. He then received a £3,500 bill.
He said: “From what I could see they only made a few phone calls. I wouldn’t advise anyone to go to them. They worked for me but it was not worth anywhere near £3,500.”
Pratt acknowledged that the organisation offered to refer callers to her husband’s consultancy but insisted that the arrangement was legal and had been properly approved.