A winner of TV show The Apprentice claimed Lord Sugar told her he did not "give a s***" when she resigned from the £100,000-a-year job he gave her when she came face to face with him at an employment tribunal.
Stella English, 34, beat 15 other wannabe apprentices to win series six of the hit BBC1 show in 2010.
She was rewarded with a role in Lord Sugar's Viglen division, supplying IT equipment to academy schools, but said that when the millionaire business mogul told her he would not be renewing her contract she was given no choice but to resign.
She is claiming constructive dismissal against Lord Sugar, describing the £100,000-a-year role she was given as that of an "overpaid lackey".
Ms English fought back tears as she said she was given no guidance about what she was meant to be doing, and was "ostracised" by her colleagues who told her she had taken over another woman's job which had a salary of £35,000.
Relegated to carrying out basic administrative tasks and with no real role, Ms English said she felt her employment was a "sham". She also said she did not feel like Lord Sugar's "apprentice" as she only saw him five times during her 13-month employment.
"My reasons for going on to The Apprentice was to be an apprentice and to be mentored by Lord Sugar," she said."I didn't believe that they would pay me £100,000 a year to do anything less than £100,000 worth of work."
She said Lord Sugar told her that he had given her the role because he did not want to damage the integrity of The Apprentice or the BBC, or to harm his own public image. Stella said he added: "But the fact is that I don't give a s***."
During cross-examination from Seamus Sweeney, representing Lord Sugar, Ms English said she did not remember being told that the winner might not work directly with Lord Sugar, adding that she understood they had in previous series.
Earlier, Lord Sugar sniggered as the tribunal was played clips of the TV show, in which he is described as "Britain's most belligerent boss".