Kate Middleton's former boss at fashion retailer Jigsaw is suing the company after the owner told her she would be "useless" as chief financial officer because she had children.
Kate Torpey is suing John Robinson for sex discrimination, unfair dismissal, and discrimination on the grounds of maternity.
At an employment tribunal in south London, Torpey told how she had enjoyed a successful career at Robinson Webster Holdings, the company behind Jigsaw and another fashion brand, Kew.
She joined the company as financial control assistant in 1996 and was made managing director of Kew in 2004.
Torpey had her first child in 2009 and was called back to work shortly after - she did not take maternity leave as she felt worried about the consequences.
She told the hearing: "John said that he thought it very difficult to do my job with a young child. He explained to me how he wasn't that involved with his children but that 'Belle [his wife] certainly couldn't do it'.
"Although I did not note it down, I also remember that he said if I wanted two children then trying to do my job would be 'totally useless'."
When she returned to work, Torpey told Robinson she wanted to work four days a week on a lower salary, which she discussed with another director, Charlie Atterton.
Prengancy not ideal
She then discovered, however, that the company was looking for a new chief financial officer.
"Charlie said he thought John wanted to get somebody new in and that he had in his mind that he would get a 'wily old man who was going to get all his reports right'."
She claimed Robinson vetoed her for the CFO role at a board meeting in January 2010 on the day she told him she was pregnant for the second time.
The prospect of her becoming CFO arose for the second time a year later, but she was pregnant again. Torpey said Atterton, told her: "It really isn't ideal."
She said that Atterton told her that Robinson was "not happy to continue" appointing her as CFO.
Torpey took sick leave with anxiety in November 2011 and resigned a month later.
Robinson denied the claims against the company, saying his decision not to give her the CFO role had "nothing to do with Kate's pregnancy". The tribunal continues.
Nick Bartlett, who worked for the company's HR department, said the business was 90 percent female and that "there were a lot of women with children" there.
The Duchess of Cambridge worked at Jigsaw as the accessories buyer between 2006 and 2007.