Mrs Hargreaves, who left school at 13 to work in a factory and was one of seven children, died in January, leaving all the money to her son, John, 51.
Mr Hargreaves, a bachelor who still lives in the house he shared with his mother, said: "It came as no surprise to me. I'd seen the money grow and we knew how much the shares were worth. My mother lived a simple life. She never took long holidays and never went abroad in her life. She preferred days out and always came home to sleep in her own bed.
"This money never made any difference to my mother's life and it won't make any difference to mine ... There will be no fancy cars or holidays for me."
He said he will not buy a new car to replace his three-year-old Vauxhall Astra. "It's a perfectly good car. Why should I buy a new one?" Mr Hargreaves said his mother had never forgotten her origins. "Coming from a poor home made her careful with money - that's why she couldn't spend it when she had it."
Robert Jordan, Mrs Har greaves' solicitor, said the estate was worth pounds 6.2m. The Inland Revenue is claiming pounds 2.3m inheritance tax. He said : "She was a delightful woman with a great sense of humour but she was very shrewd and knew what she was doing. I remember a number of years ago telling her that she was worth millions - and all she did was giggle."Reuse content