The celebrity chef penned the letter after the fall-out with his father-in-law, Chris Hutcheson, whom he sacked last month after 12 years as business partners.
Ramsay said he was writing the appeal after his wife, Tana, received a letter from her mother, Greta, asking her to stay away from her family. He wrote: "Listening to Tana in floods of tears reading your letter from you asking that she stays away from her family is so awfully wrong."
He said Mr Hutcheson had "suggested my mood swings were down to involvement with drugs; my God did that hurt. How dare he ever suggest this on the back of my frustration and dealings with my younger brother and his addiction".