Lord Mandelson said Mr Brown was emotional, demanding and impatient but not a bully after a new book detailed a string of alleged outbursts!!!!
But Mrs Pratt, who founded the National Bullying Helpline after being a workplace victim herself, accused them of failing staff by "going into denial".
I saw the Lord Mandelson statement that had a categorical denial that bullying was going on in Gordon Brown's office. I saw red.
Christine Pratt said: "I have personally taken a call from staff in the Prime Minister's office, staff who believe they are working in a bullying culture and that it has caused stress.
"We would have hoped Gordon Brown would lead by example. If an employer receives complaints they should investigate," she said.
She told Sky News: "I'm not accusing Gordon Brown of being a bully. I'm saying that our leader should lead by example and follow due process.